Differential parts compatibility - DISCUSSION

[roadrash]

It just occurred to me that one of the common questions here is "I want to swap to X differential, will it work with Y half-shafts, and Z drive shaft, etc.?"

Since I'm probably going to have some free time next week, I'd like to try to compile a table of the existing "known to work" combinations of swapped differentials etc. on the cars here. and put it in the knowledge base somewhere.

So, the first task is to come up with a list of what data needs to be gathered. How about the following...

What type of transmission? (auto/manual, Getrag, ZF, etc.)
Drive shaft came from what year & model car?
Diff. ratio
Diff. case size
Diff. was taken from what year & model car?
What type of diff. cover?
Diff. cover was taken from what year & model car?
Output flanges were from what year & model car?
Half-shafts were taken from what year & model car?
What modifications did you have to do?
Have you had any issues with this combination?
Misc. Notes


Are any of the above unnecessary?
What else needs to be added to the above list?

AFTER we get a list of all the questions that need to be asked, I'll start gathering data and put it into a table of some sort. So, hold on to your data for now. :biggrin:

Once I see the data, I'll have a better idea what format would work best. At the moment, I'd like to be able to create an Acrobat file (PDF) so that it can be printed out easily. But, I might also have it in a generic HTML table and/or a spreadsheet. Any thoughts on that?

JMJ

====================

This is the "listings" thread in the Knowledge Base. (http://www.318ti.org/forum/showthread.php?t=28958)

[KINGAMR]

I just had to deal with a similar situation & learned it the hard way so I might have enough info for you.LMK

[roadrash]

Cool... do you have any suggestions on what data that needs to be gathered? I.e., what needs to be added to and/or left out of the list of questions?

[KINGAMR]

I think that's a pretty good list of questions,however there's only a few choices of setups to run. Usually the output flanges & half shafts match, Z3 M diff cover or E30, plus of course the choice of small or medium case diff with desired gear ratio. I could be wrong but that's what I can sum up from my experience.

[pdxmotorhead]

Maybe each person who has done it, should just post their list of components?

Dave

[roadrash]

Well, yeah... that'll be fine as long as there is some order to it. I want to make sure the "questions" are satisfactory first, so that I don't have to go back and ask everyone for one more bit of data. :-)

Can you think of anything relevant to add to the list? ... or anything that's on the list but isn't relevant? I'm sure I'll ask that a few more times because I've never done a diff. swap so I don't have any first-hand knowledge of what is required.

[tiFreak]

maybe the date of manufacture on the car and whether or not the bottom of the car had to be modified to fit the diff, I know later ti's you didn't need to do anything but I'm not sure what the cut-off date was

[pnosker]

2.93 from E30, running stock half shafts and ti flanges, stock DS

3.23 from E28, E30 cover, stock half shafts and ti flanges, stock DS

[Xenocide]

2.93 from E30, running stock half shafts and ti flanges, stock DS

3.23 from E28, E30 cover, stock half shafts and ti flanges, stock DS

yup, had to do some body mods with a sledge hammer on a 9/95 build date.

[roadrash]

Hmmm... I know there will need to be a "miscellaneous notes" field, perhaps body mods would go there.

Thanks for the tip... anything else?

I probably won't be able to work on this for the next couple of days so now is a good time to work out what questions need to be asked and what data needs to be gathered. :-)

[cooljess76]

If you go with a medium case diff, you REALLY should use e30 halfshafts. They're beefier and fit much better. People who have ran ti halfshafts with medium case diffs have had issues ranging from halfshafts breaking under load to having to force them to fit.

e24, e28, e30(6cyl models), 2.8L Z3, MZ3 and Mcoupe's all have medium case diffs that will fit on the 318ti. 4cyl e30's came with small case diffs as did the 318ti and I think the 1.9L Z3. REGULAR E36(coupe and sedan) DIFFS WILL NOT FIT.

2.8L Z3's, MZ3's and Mcoupes have Torsen style Limited Slips while e24's, e28's, and e30's have clutch style limited slips. 5speed e24's came with 3.46 LSD's, 5speed e28's came with 3.25 LSD's and 5speed e30's came with 3.73 LSD's. Stock diff ratio for the 5 speed 318ti is a 3.45. As you know, some models came with open diffs and some came with LSD's. A thing to consider when choosing a ratio is engine RPM vs. speed. The stock 3.45 diff runs around 3800rpm @ 80mph. Lower numbers ie; 2.93, 3.25 etc, will lower the rpm's while increasing your top speed and fuel economy, but will make you slower/sluggish off the line. Higher numbers such as 3.73, 4.10, 4.44's etc, will increase your rpm's, thus lowering your top speed and fuel economy at highway speeds, but you'll take off like monster off the line. If you want to lower your rpm's at highway speeds but maintain decent power at cruising speeds, go with a 3.25 LSD. If you're happy with the Ti's stock gearing, go with a 3.46 LSD. If you're doing an engine swap, keep in mind M3's, Mcoupes and M roadsters come stock with 3.23 LSD's:wink: 318ti's came with 3.45 open and LSD's to compensate for their lack of power. BTW, there's plenty of "final drive calculators" floating around the internet. If you want to find out what your RPM's will be at certain speeds with different setups, just google "BMW final drive calculator". Here's the first one that popped up when I searched a minute ago: http://368s.com/tools/rpm Just type in your final drive ratio, enter your tire size and click calculate. 1st through 4th gear ratios may differ between the Getrag and the ZF trannys, but I think 5th gear is 1 to 1 on most BMW's.

There's two markings that will identify a LSD. First being an "S" on the identification tag. This tag is located on the differential cover, held on by one of the cover bolts. It will either say 3.xx if it's an open diff or S3.xx if it's limited slip. Another marking that will help you identify a LSD is an "S" painted on the top of the differential case. However, you won't be able to see it unless the diff is removed from the car. It often gets covered with road grime making it difficult to see. The easiest way to identify a LSD is to spin one of the output flanges. Not the input flange on the front, but one of the flanges that connects to the halfshaft. If both sides spin in the same direction, it's a LSD. If one side spins in the opposite direction, it's an open diff.

Another thing to note, if you go with an e24 or e28 diff, you'll need to purchase an e30 cover, speed sensor and output flanges in addition to the previously recommended e30 halfshafts. Reason being, e24/e28 halfshafts/output flanges have a different bolt pattern and won't work with e30 halfshafts. The output flanges pop right out, no tools required.

The 318ti uses an e30 style differential carrier, so the e24 and e28 diff covers won't fit. The e30 cover fits perfectly and is the same cover used on the 2.8L Z3 diff. MZ3's and Mcoupe's also have an e30 style cover that works, but they're usually pretty expensive due to the massive heatsink that is built into the cover. This heatsink hangs below the diff and I've yet to see one on a lowered car that isn't damaged.

The setup I'm running and I highly recommend is an e24 3.46 LSD with an e30 cover, e30 halfshafts, e30 output flanges and an e30 speed sensor. Reason being, the 3.46 LSD is really close to the stock ratio of the 318ti diff. The e30 cover fits perfectly and doesn't hang too low. The e30 halfshafts and flanges fit perfectly like it was meant to by the factory, since the medium case diff is wider than the stock 318ti small case, the shorter e30 halfshafts allow full range of movement as opposed to force-fitting the longer 318ti halfshafts which will restrict the necessary pivot range and cause excessive stress on the CV joints. And the e30 speed sensor is plug and play with the 318ti connector(at least mine was), there's different styles of connectors, you need the one that is round on one side and square on the other and it needs to be the same length as the one that originally came out of the diff that you're going to be using.

All Z3, MZ3 and Mcoupes came with LSD's. NOT ALL e24's, e28's and e30's came with LSD's, so make sure that you check for the markings or spin the output flange/shafts before purchase one.

Also, if you're installing e30 halfshafts, be sure that they came off a car with ABS. You can identify ABS halfshafts by the gear-like tooth'd ring on the outer end that mates to the wheel hub. This is called an ABS "tone ring". The ABS sensor(s) also called "pulse generators" sit about 1mm above the tone ring and receive a magnetic signal from the tone ring. Since the e30 halfshafts are larger in diameter(although shorter in length), the tone rings are also significantly larger than the 318ti tone rings. This means that you will have to "shim" your stock ABS sensors so they don't rub the tone ring and become damaged/destroyed. It's really easy to do, I just used a flat washer with a 5/8" hole. The sensor fit perfectly snug in the hole on the washer and I modified the washer with a dremel tool so the sensor would bolt back up to it's original location on the trailing arm. IIRC the washer needs to be 2.25mm thick and it should space the sensor perfectly from the tone ring on the halfshaft.

As for the drive shaft, if you're running the stock Getrag transmission, your stock 318ti driveshaft will work just fine with the medium case diff. If you're running a ZF tranny like most of us 6cyl swapped guys, you'll need to mix and match driveshafts since the ZF tranny is about 1 1/2" longer. I think the 318ti rear section with an M3 or 328 front section will work fine(again, this is only if you're running a ZF tranny).

Most of the diferentials that I mentioned have the same 4 bolt input flange as the 318ti. Some of the MZ3 and Mcoupe diffs may have a 6 bolt input flange that will need to be swapped.

That's all I know about BMW diffs, I hope I answered most of your questions:wink: If anyone feels I'm mistaken, please feel free to correct me.

[roadrash]

Jess... do you have any additions/subtractions to the list of "data to gather" that I proposed in the first post?

[cooljess76]

Jess... do you have any additions/subtractions to the list of "data to gather" that I proposed in the first post?

I think you've pretty much covered it. Perhaps weight and brand of gear oil used may be helpful. Oh yeah, year and model of the 318ti will help since certain years needed the floorboard modification.

[Bluebimma]

04/1997 318ti Active
M44B19 (stock) M50B25 (installed)
Getrag 5speed
E28 3.25LSD
Motorsport Finned differential cover
Stock driveshaft
318ti Axles
lowered 3" in the rear
No issues

04/1997 318ti Active
M44B19 (stock) M50B25 (installed)
Getrag 5speed
E30 4.10LSD
Motorsport Finned differential cover
Stock driveshaft
318ti Axles
lowered 1.5" in the rear
Had issue with inner dust cover tearing open because the ti shafts are too long when lowered

07/1996 318ti Sport
M44B19 (stock) M50B25 (installed)
GM 4l30E Automatic 4speed overdrive(stock) Getrag 5speed (installed)
E30 4.10LSD
Motorsport Finned differential cover
Stock driveshaft
318ti Axles
Stock ride height, no issues
Had to modify floor board of hatch to clear a bolt for the differential cover at the top.

[roadrash]

I think you've pretty much covered it. Perhaps weight and brand of gear oil used may be helpful.
Gotcha, added that.

Oh yeah, year and model of the 318ti will help since certain years needed the floorboard modification.
Good point. In my head "model" meant "year and model." I fixed that above.

OK, give me a couple of days to get in the groove of this new tour and I'll figure out how I want to gather and display the data, etc.

[KINGAMR]

My setup: An S3.46 diff from an e23,e30 diff cover, AKG 75D diff bushing, e36 sensor, E30 axles and mobil 1 75w90 with LSD additive going in a 6/96 318ti. Successful diff swap threads need this!;)
http://i366.photobucket.com/albums/oo106/kingsparts/96%20%20318ti%20swap%20pics/6cylinderdifferentialch1.jpg

[projekt EPiK]

great work Jess and everyone else. Good reading here.

[roadrash]

OK... I started the listings thread. Please send your info to me (or post it here) in the following order and I'll add it to the listings thread:


What is the production month/year of the 318ti that this is going into? (e.g. 6/96)
What type of transmission? (auto/manual, Getrag, ZF, etc.)
Drive shaft came from what year & model car?
Diff. ratio
Diff. case size
Diff. was taken from what year & model car?
What type of diff. cover?
Diff. cover was taken from what year & model car?
Output flanges were from what year & model car?
Half-shafts were taken from what year & model car?
What modifications did you have to do?
Have you had any issues with this combination?
Misc. Notes


If you don't have any info for a particular number, include the number anyway so I can more easily copy/paste the data into a spreadsheet that will eventually provide a PDF file. E.g.,

10 - 1987 325i with an auto tranny
11 -
12 - the case cover had a crack that I didn't notice and leaked, but I got that fixed.

This is the "listings" thread in the Knowledge Base. (http://www.318ti.org/forum/showthread.php?t=28958)

[Bilal]

ok. here is my setup and i still have wok to do..

'94 318ti.. well it was
now it has M50B25 motor with M20 transmission . I still have th 3.45 rear diff but I just bought (still waiting for it) a 3.07 diff from the 323ti.

so the question is:

which half shafts do I use. The 323ti or can I get by with E30 325?

[cooljess76]

ok. here is my setup and i still have wok to do..

'94 318ti.. well it was
now it has M50B25 motor with M20 transmission . I still have th 3.45 rear diff but I just bought (still waiting for it) a 3.07 diff from the 323ti.

so the question is:

which half shafts do I use. The 323ti or can I get by with E30 325?It really depends if the 323ti came with a medium case differential. If it came with a small case differential like the 318ti, you should use the 323ti halfshafts. If it came with a medium case, you can use either e30 325 or 323ti halfshafts.

Roadrash, you should post a link to the listings thread at the beginning of this thread:wink:

[RAiMA]

The majority of the stuff I used was from the 2.8L Z3. They're beefier than the normal gear

[Bilal]

It really depends if the 323ti came with a medium case differential. If it came with a small case differential like the 318ti, you should use the 323ti halfshafts. If it came with a medium case, you can use either e30 325 or 323ti halfshafts.

Roadrash, you should post a link to the listings thread at the beginning of this thread:wink:

It has what we over here call the "big" pumpkin.. the 318th has the "small" pumpkin. So I wll just use the E30 325.. they are easier to get.

[roadrash]

Roadrash, you should post a link to the listings thread at the beginning of this thread:wink:
Well, duh, yeah, that would be a great help, huh? LOL

Here's the listings thread. (http://www.318ti.org/forum/showthread.php?t=28958) I closed it so you'll need to post your info here, or send it to me.

Thanks for the awesome submission, Jess! I knew I could count on you to be thorough and set a good example for the other kids to follow! :-D

[Bilal]

The 320 shfts I used it.. but the problem I didnt think of.. the shafts need ABS sensors...

[roadrash]

Thanks for your submission (http://www.318ti.org/forum/showthread.php?p=259465#post259465), pnosker!!

[1996 318ti NY]

Alright im in the process of doing a full swap, and i have e30 shafts and an e30 3.73 lsd in the garage. Now i have the stock lsd out and im trying to figure out how to take out the stock half shafts do they jsut pull out? or do i have to do something? I dont want to break anything so advice is needed also the e30 half shaft can be used without using parts from the ti shaft?


V/R Paul

[Bluebimma]

........Seriously, rewrite that.

[1996 318ti NY]

Re-done for Blue that had to make me use my comp -.- LOL

[Bluebimma]

Did you read the DIY on how to swap out the diff? I wrote one in the diff section, not stickied. The stubs pop out and the half shafts require you to remove the nuts from the hubs, and to be knocked out so new ones can be installed.

[1996 318ti NY]

there are bolts holding it in on the wheel end of the half shaft? im gonna search your DIY now, thanks.

[sam can man]

thanks for some feed back. I still have not done my homework on my own car yet but i want less power, more fuel efficent! totaly opposite than normal but i guess that i am into recycling tooo much.... Anny help??? 98 318Ti manual transmission. PLEASE HELP ME all i want is to go 80-90 on the highway and have my RPMS ALOT lower!

[pdxmotorhead]

Mine gets about 27 at 80... Good enough for me...The M44 and M42 don't like low rev lugging. Wrong tool for the job...


Dave

[cooljess76]

The M44 and M42 don't like low rev lugging. Wrong tool for the job...


Dave+1, Lowering the RPM's doesn't necessarily improve fuel economy. While it may help you in 5th gear at highway speeds, you have to consider city driving and stop and go. If you're struggling to take off and get up to speed, you're wasting more fuel than you'd be saving on the highway. Couple things you can do to conserve fuel, replace your o2 sensor(s), replace your air filter, check/replace you spark plugs regularly, correct tire size & pressure, and most importantly have a light foot.

I've heard so many people ask why their gas mileage sucks, only to see them driving their car like it's a rally car. Take it easy. I mean it's cool to stretch your engine out once a week, I do it, but hey if you're always in a rush to get somewhere, perhaps you can just plan your day out a little better. You'll notice the rewards at the pump if you'd simply slow down.

And finally, maybe not a practical option, but it's been tested and proven that some forced induction applications have actually shown improvements in fuel economy. Now this doesn't mean if you supercharge your car you're gonna get great gas mileage. Most people install superchargers and what's the first thing they do? They go out and try to race everything on the road. Well there went fuel economy right out the window about seven blocks back there.

But yes, if you have a supercharged or turbo'd engine WITH PROPER TUNING, you will notice a significant increase in fuel economy provided you don't drive like a maniac. The reason being, your engine will burn fuel more efficiently as it takes less energy for the engine to get your car up to speed and maintain it. However, I should remind you about not being practical. Considering that a supercharger costs $3800, how many miles would you have to drive before you save that much in fuel costs? Probably a couple hundred thousand:cool: Then you have the reliability issue. Most forced induction applications need special maintenance such as turbos/blowers being rebuilt/replaced. They usually result in abnormal or excessive wear on other components that are forced to work a little harder.

I just realized this is a diff thread, so I'll try to get it back on topic. E28 3.25 open or LSD, E30 rear cover, E30 output flanges, E30 halfshafts, shimmed ABS sensors, new diff cover seal, fresh gear oil = lower RPM's @ highway speeds and reasonable acceleration around town:wink:

[Bluebimma]

My clubsport saw well over 35mpg at 80mph on the trip from new hampshire to toledo, ohio. Also, my m50 with a 4.10 rear end made nearly 30mpg at the same rate of speed. Its not about the revs, its about its tuning and what its designed for. These arent american cars, that require low rpms to sip gas efficiently.

[PrimeTimeSlime]

Do any of y'all know if a small case 3.45 lsd from a 92' 318is is a direct swap with the 318ti (1996)? I have searched a ton but I cant really find a definitive answer.

[cooljess76]

E36 coupe/sedan diffs WILL NOT FIT the Ti:
http://i135.photobucket.com/albums/q122/cooljess76/diffs.jpg

http://i135.photobucket.com/albums/q122/cooljess76/diffs2.jpg

[PrimeTimeSlime]

Jess, Awesome post man! That was exactly what I was looking for. Muchos Gracias!

[cooljess76]

Jess, Awesome post man! That was exactly what I was looking for. Muchos Gracias!

No problem. I should've did that a long time ago:wink: Regular e36 diffs mainly don't fit because the subfames are completely different due to the e36 coupe/sedans using multi-link rear suspension and the Ti, Z3 and e30's using semi-trailing arm rear suspension. I believe Rogue Engineering makes a kit that allows us to use a dual ear cover, but you still have to use the e30 style diff. Haven't heard of many 318ti's having problems with the subframe tearing out of our floorboards like they do on the Mcoupes and Z3's. The e36 coupes and sedans are known to have subframe failure, and they use the Dual Ear diff covers???

[sam can man]

jess i apreciate the computer link ... now if i nly new how to use the computer and knew how to read.. can you shoot me an e mail @ samjadczak@yahoo.com and give me a # to call and I want to ask some domb questions about my 98 318 tI i have alk ot of ideas but KNOW where to start from but hear say?!!!

[dave45056]

I have something to contribute here... I noticed that the LSD unit inside a regular e36 small cased diff (from a 318i or is) is the same as the LSD unit inside the ti diff.

[sam can man]

thank u every one!!!! one mor question ,,, after reading all of that,,,, I want limited slip in my rear with new gear oil/!??!!!!!!!!!!!!! can i take the guts out of the 95 318 iS auto and adapt the limited slip gearing into my diff case that is allready on the 98 bmw?

[cooljess76]

thank u every one!!!! one mor question ,,, after reading all of that,,,, I want limited slip in my rear with new gear oil/!??!!!!!!!!!!!!! can i take the guts out of the 95 318 iS auto and adapt the limited slip gearing into my diff case that is allready on the 98 bmw?Hey sam, although I've never done it before, I'm pretty sure it can be done since both diffs are small case diffs. The ring and pinion should be the same size so you should be able to use the stock 3.45 gears with the limited slip out of the 318is diff.

[spidertri]

I'm considering picking up an e30 small case 4.10 lsd from a 91 318is. Would it be a direct swap for my current stock small case diff? I should be able to reuse my diff cover, flanges, and half shafts, correct? The price for this diff is just too good to pass up if it will bolt up easily.

[cooljess76]

I'm considering picking up an e30 small case 4.10 lsd from a 91 318is. Would it be a direct swap for my current stock small case diff? I should be able to reuse my diff cover, flanges, and half shafts, correct? The price for this diff is just too good to pass up if it will bolt up easily.

Yeah Dave, it'll be a direct swap since it's a small case e30 diff. You won't need to swap the cover or halfshafts, but you may need to swap the output flanges if the bolt pattern doesn't match your current halfshafts. The output flanges pop right out, no tools required other than a wrench or screwdriver to pry them out of the case with. Just use a sharp jerking motion and they'll come out, but again, you might not need to if the bolt pattern matches. Is your car an automatic? If so, 4.10 will nicely lower the rpms to a comfortable range @ highway speeds.

[spidertri]

Cool, that's what I was hoping you'd say. My car is manual. I've been playing with the gear ratio calculator and I'm still deciding if I'll be able to handle the new highway rpms.

[cooljess76]

Cool, that's what I was hoping you'd say. My car is manual. I've been playing with the gear ratio calculator and I'm still deciding if I'll be able to handle the new highway rpms.It's gonna rev pretty high, I think Bluebimma ran a 4.10 for a while. Marv17 ran his stock 4.44 for a couple days after swapping in an S52 and ZF 5speed. He said the tach was pegged out at highway speeds and the gears were so short the car was practically undriveable, lol. You might consider swapping the ring and pinion gears between the two or swap the LSD into your current diff. It's a pretty tedious task though.

[spidertri]

That's an interesting idea, swapping the ring and pinion gears. Stock is 38:11 and the 4.10 is 41:10. I could go with a 41:11 or 38:10, which would give a 3.72 or 3.80, respectively. I'll have to look into that.

[Bluebimma]

4.10 is not undriveable, ive done it for the past 2 years. I still get 24 city, 32 highway with the m50.

[sam can man]

yay gay how it is so great that every thing bmw interchances,,, sory for the misspelling bmws are so great, you can customise to the whay u want

[wolferj-RIP]

I just completed the final drive swap...

Used e30 325is med case diff with 2.93 LSD, output flanges, e30 M3 half shafts.

[DaveKern]

I've got a couple questions for you diff swap experts. Here's a little background first:

I'm building a rally car - i.e. competition only
I'm swapping to a MkIII Supra rear diff b/c ring & pinions are just $140 new...even high ratios
I'm going to be running a 4.56 ring & pinion
I need to have custom adapter rings made where the axles bolt to the diff, and need to know how thick to have them cut.

I see that when folks upgrade from the small to the medium diff that using E30 6-cyl axles is needed. Can someone tell me how much wider the medium diffs are? How much shorter are the axles?

I have measured the width of the small diff at the axle mounting surface and they are 10.25" wide.

Thank you,

Dave

[spidertri]

I just measured my E30 3.73 and it was 11" wide. I don't have the E30 axles yet so I can't help there.

Edit: Got the axles, they are 22 3/4".

[Fuzzy Nutbucket]

Ok so pulled the differential and axle shafts out of my ti so I can swap in an e30 2.93 LSD unit and e30 6cyl. axle shafts. (for my s50b30 swap) How ever the length from the face of the input flange to the center of the front mount holes is about a 1/2 inch or so longer then the small case diff that was in there, after fighting with it for a half hour or so I gave up for the night, and figured I'd see if anyone here has any input, help or ideas for me. I'm totally stumped here, and on a side note, can i swap speed sensors so that the plug will work or should i just by a plug with a pig tail and splice it in place? Any and all input, ideas, or help is appreciated!
Thanks!!

[wolferj-RIP]

FNB-

I did the exact swap you are doing. It was a very tight fit, and I, too thought the e30 case was longer, but after triple checking and swapping the input flange, it fit. Ended up loosening the driveshaft center bearing so there was some play, and that helped get it in place. Also needed to make a little rear clearance room at the back of the diff by whacking a small cross beam a couple of times.

[Fuzzy Nutbucket]

Hey Wolferj,
Thanks, what did it take to swap the input flanges? Looking at it I figured that it would fit fine as far as the chassis cross bit was concerned as long as the drive shaft was like, 1/2in. shorter. but i was just eyeballing that. What about where the torque mount (big "ear")on the rear cover mounts up, did that have to get bent out any or no?
Thanks again!

[wolferj-RIP]

Hey Wolferj,
Thanks, what did it take to swap the input flanges? Looking at it I figured that it would fit fine as far as the chassis cross bit was concerned as long as the drive shaft was like, 1/2in. shorter. but i was just eyeballing that. What about where the torque mount (big "ear")on the rear cover mounts up, did that have to get bent out any or no?
Thanks again!

Well, the input flanges turned out to be the same. I, like you, thought that when I looked at them, the med case was longer and the flange was the culprit. However, there is no difference in overall length for the input section. My issue is that the trans sits back a little farther due to the 6 cyl swap, so an adjustment at the central joint did the trick. We did expand the width of the ear mount, but it was just to give a little more manuver room to get the diff in place. The chassis cross is only an issue for 95 models (like mine) to make a little room for clearance for the top cover bolts, not the mounting bolts.

[Fuzzy Nutbucket]

Well I know that the trans. is sitting back farther due to the s50, like you said, and that the DS did suck up a little but I'm not sure there was enough length left for it to shortn' any more. Plus that was infront of the center bearing, can the bearing mount move, I don't recall if it was slotted or not...

[318ti808]

I am looking at buying a 1995 318ti with a 1999 s52 modified with a 95 intake. It is running the stock trans and drive line as well as the stock rear end. Would like input on the rear end. I have J!ms swap manual which highly recommends changing out the diff as it could go at any time. I also emailed him and he recommends the same. I am purchasing the car from Sacramento, Calif and shipping to Hawaii so getting parts in Hawaii is not easy. The PP seller is willing to help out by swapping in a M3 coup rear setup or the appropriate diff from a 325i. I am looking at $355 for diff and install vs $1500 for the full upgrade. The car purchase price is $7800 (has suspension mods struts and shocks all around. He is throwing in M3 front suspension and brakes that I will install). What is the experience of running the stock rear end? I have seen a couple of recent posts that indicated they have run the stock rear end for a year. Any other input would be greatly appreciated.

What happens to the rear end that blows up, too much pressure and blows the rear cover? grinds up the gears due to too much torque?

Any comments/ adivse would be appreciated.

Any one with swap knowledge in the Sacramento area that would be willing to go look at the car for me?

I had the local dealer do a pre-inspection purchase, which noted some minor repairs such as trans mounting and guibo replacement, but other than that it looks good mechanically. Dealer was not able to hook it up to their computer however as that was not functioning on the car, bummer. I am basically purchasing sight unseen, although I had a good buddy check it out for me for general body and interior looks and condition. The ti body has 185,000 but is in good shape. The motor has under 23,000 miles and 75% of the reason I want the car. My dream car is a 1998 or 1999 M3 convertible, so this motor could fill part of that dream. I already have the hardtop for the convertible sitting in my sister's garage in Sacramento.
Norman

[cooljess76]

Any number of things can cause diff failure and the results can be as minor as howling, chatter or grinding and as major as the thing exploding, locking up causing you to wreck, bent or snapped driveshaft, damaged transmission, ujoint damage, axle damage, subframe damage, or worst case scenerio... pole vaulting your car off the highway, lol. The ring, pinion and planetary(spider) gears are much smaller in the stock small case diffs and will not hold up to the added torque of the 6cyl engine. Bearings could wear out causing things to lose their alignment, metal can fatigue from overheating or low oil levels, teeth can snap off of the gears, shrapnel can get sucked into the ring, pinion or planetary gears. There's a reason why BMW put medium case diffs in their 6cyl cars. While it may hold up for a while, failure is inevitable. Think of it as a ticking time bomb. When it goes, you might get lucky and catch it in the early stages, or it might just cause you to wreck.

[318ti808]

Jess
thanks for your input.... the howling of the gears as warning is good; the balance - aaah I will definitely at the minimal have the 325i rear end swapped before I have it driven to the dock to ship.

[cooljess76]

It should be fine for a little while as long as you take it easy and don't romp on it too hard.

[tiFreak]

The PP seller is willing to help out by swapping in a M3 coup rear setup or the appropriate diff from a 325i.

unless those are parts out of an E30 they won't work in the ti

[maverick]

Okay, lt me get this straight as I have heard all sorts from all sorts of places. I have a 3.73LSD medium case out of an e30 325 that I want to put in my 96 318ti. It seems reading it all here that my best bet is the 3.73, using e30flanges, e30 halfshafts and e30 stub axles, shimming the ABS and thats about it, am I right??? Do I have to change bearings or anything for the stub axles, or just remove the nut and swap with new retainer?

Sorry if I sound ignorant but i am on this one as if a fool listens to too many fools he is follish, and it seems this is a very good source for the staright story.

Dave

[cooljess76]

Okay, lt me get this straight as I have heard all sorts from all sorts of places. I have a 3.73LSD medium case out of an e30 325 that I want to put in my 96 318ti. It seems reading it all here that my best bet is the 3.73, using e30flanges, e30 halfshafts and e30 stub axles, shimming the ABS and thats about it, am I right??? Do I have to change bearings or anything for the stub axles, or just remove the nut and swap with new retainer?

Sorry if I sound ignorant but i am on this one as if a fool listens to too many fools he is follish, and it seems this is a very good source for the staright story.

DaveYou're good Dave, that's everything you need to do and the diff should work fine. I'm pretty sure you'll need the e30 speed sensor and you should also change the gear oil and rear cover gasket. Since your car is a '96, you may or may not need to hammer the cross beam under the floor pan.

[kuleinc]

I have a 95ti with some random open diff in the back, I'm pretty sure its rubbing on the floor (ie no hammering done) because you can "hear" the engine rev from the trunk, its quite amusing... does anyone have a chart of which diff ratios give you what engine speed at 65 mph?

[cooljess76]

I have a 95ti with some random open diff in the back, I'm pretty sure its rubbing on the floor (ie no hammering done) because you can "hear" the engine rev from the trunk, its quite amusing... does anyone have a chart of which diff ratios give you what engine speed at 65 mph?

random open diff? did someone swap out the original? You say it's rubbing on the floor, so i'm assuming it's a medium case. There's usually a tag attached to the rear cover which will have the ratio stamped on it, but you can also jack both wheels up, put it in nuetral, spin the driveshaft and count how many rotations it takes to make the wheels spin one complete rotation. Obviously, make sure the car doesn't fall on you since it will be in neutral and the parking brake will be disengaged. As for finding out ratios vs speed vs rpm, just do a google search for a "BMW final drive calculator".

[kuleinc]

I was hoping to find a chart to look at :cool:

[spidertri]

The speed depends on the transmission ratios, diff ratio, and tire size. I don't think you'll find a chart. I have a spreadsheet that calculates everything if you search google like Jess said you'll find it.

[kuleinc]

Im thinking 3.45 or taller, just worried the car will be too slow, or too droany on freeway. It's hard to choose when u haven't tried each ratio....

[cooljess76]

I was hoping to find a chart to look at :cool:

Did you even search? I just googled "BMW final drive calculator" and this was the second on the list of hits:
http://www.bokchoys.com/differential/GearRatios.htm

Find 318ti auto or manual(whichever one you have), plug the numbers into this calculator(4th on the list of hits)
http://www.google.com/url?sa=t&source=web&cd=4&ved=0CCoQFjAD&url=http%3A%2F%2Fwww.car-videos.net%2Ftools%2Fspeedrpm.asp&ei=yZ2LTbu7LYy0sAOazNiRCQ&usg=AFQjCNHYGv5RVtecpLQqhImdmmznsLXGRQ

click "recalculate" and you should see a chart with speeds listed according to RPM and transmission gear.

Here's what it looks like, however your results may vary depending on YOUR tire size and final drive ratio:

[kuleinc]

I'm at work with my phone, I'll search or check it out when I get home tonight

[RCV7]

Hey, guys. I just read this whole thread. Very informative. I'm a noob so please bare with me. I have a stock '96 Ti active. I"m about to purchase a Z3 2.8 engine and a ZF trans from an M3 complete with clutch and drive shaft. I gather I can't use either difs from my ti or the donor M3. I'm Looking to get an LSD dif.
1. Can I use a Z3 6 cylinder dif and if so which ratio would be best and easiest to bolt up? I'll be using both 16 and 17 inch rims with low profile tires.
2. What kind of gearing would a 3.15 from a Z3 give me with this setup?
3. Should my hybrid drive shaft be from my existing ti and an M3, 328 or Z3? I really don't want high rpms at speed or the opposite. This will be my dd as well as autox and some track. Your thoughts are appreciated. Thanks in advance:biggrin:

[maverick]

Hey, guys. I just read this whole thread. Very informative. I'm a noob so please bare with me. I have a stock '96 Ti active. I"m about to purchase a Z3 2.8 engine and a ZF trans from an M3 complete with clutch and drive shaft. I gather I can't use either difs from my ti or the donor M3. Can I use a Z3 dif and if so, auto or manual and which ratio would be best and easy bolt up. I'll be using both 16 and 17 inch rims with low profile tires. I really don't want high rpms at speed or the opposite. This will be my dd as well as autox and some track. Your thoughts are appreciated. Thanks in advance:biggrin:

You can use the one from the Z3 if it was a 6-cyl car as if a 4-cyl likely the same diff in the ti and it will fail more than likely with a 6-cyl feeding it. The ZF I am not sure about as may change the drive shaft length, maybe someone knows more on that than me. If you don't want revs and the ZF is a 5 speed you want a manual diff and likely no more than a 3.23 or somethin in that area. If you want more power then you have to deal with higher revs.

Some body else can refine this maybe.

Dave

[bmorekirby]

ok. so how big of a hammer do i need to beat in the subframe? i have a 4 pound maul i tried, and it didn't cut it.

thanks,
john

[cooljess76]

ok. so how big of a hammer do i need to beat in the subframe? i have a 4 pound maul i tried, and it didn't cut it.

thanks,
john

Hey John, don't beat on the subframe, it's the floorboard above the subframe that hits on older models.

[vwmikel]

This seemed like a good place to put this. I just swapped a medium case 2.93 LSD into my 5/95 TI.

http://i700.photobucket.com/albums/ww1/vwmikel/diff2.jpg

http://i700.photobucket.com/albums/ww1/vwmikel/diff1.jpg

As I found in another thread the bolt that lands toward the drivers side actually is what interferes with the rear floor of the car. The other person had countersunk both of the top bolts, but with the vent right there it seemed pointless on the one that is toward the passenger side. So, I just countersunk the one bolt and pushed the vent down a bit using the press. I ended up not having to pound on the floor or anything, but the mount itself (the one that hangs down from the car) was still in the way. I did some clearancing in there using a chisel so that I didn't have to pull the diff back out. If/when I have to pull it out again I'll smooth that out with a grinder. Otherwise, I hear no additional noise or vibrations even with the poly mount (street density). On a side note, it might be better to use studs and nuts or at least use studs just to locate the differential as getting the bolts started was a pain.

[PrimeTimeSlime]

Hey guys, been reading a lot about the LSD swap and I just want to verify one thing.

Swapping a 2.8 m52 and zf transmission this week. While I am at it, I am swapping a 3.73lsd from an e30 325is into my ti.

I plan to take the 318ti output flanges and put them in the e30 diff, then use the 318ti half shafts. Sounds simple enough, will it work?

Thanks

[cooljess76]

Hey guys, been reading a lot about the LSD swap and I just want to verify one thing.

Swapping a 2.8 m52 and zf transmission this week. While I am at it, I am swapping a 3.73lsd from an e30 325is into my ti.

I plan to take the 318ti output flanges and put them in the e30 diff, then use the 318ti half shafts. Sounds simple enough, will it work?

Thanks

I wouldn't recommend it. The 318ti halfshafts are longer than the e30 halfshafts since the small case diff is narrower than the medium case diff. I've heard of people swapping flanges and forcing the ti halfshafts into place, but doing so puts more stress on the CV joint. The solution would be to use 6cyl e30 halfshafts, but you'll need to shim your ABS sensors. Whichever route you go with, be sure to use NEW output flange bolts and properly torque them.

[PrimeTimeSlime]

I was afraid you would say that.

This is what is confusing me.
http://www.318ti.org/notebook/diff_conversion/index.html

This guy says that the e30 half shafts are longer than the 318ti's.

Someone else told me you can make the ti half shafts fit by breaking the abs rings off and just going without abs. I think I could live without abs in the rear.

[cooljess76]

Yeah, I remember reading that a long time ago. I had both halfshafts side by side and I can say from experience that the e30 shafts were shorter. It doesn't make sense that a small case diff would have shorter shafts than a wider medium case diff. ABS is a very important safety feature. I wouldn't even drive a vehicle without ABS. Maybe on a rally car or track car, but definitely not a passenger vehicle on public roads. You'd be putting everyone at risk.

Like I said though, there's been a few people who used the ti halfshafts with medium case diffs. Personally I don't think it's a good idea at all. Doing so will put a lot of excessive stress on the cv joints.

[PrimeTimeSlime]

Got it. For some reason I was worried that the abs shim was a PITA. looks like it is just a washer though. No biggie.

Thanks for the help Jess.

[RCV7]

I just swapped in a Z3 2.8 aluminum block M52 with the matching ZF 5 speed. I also installed the whole rear sub-frame assembly from the Z3 with the larger 3.15 dif. I used the Z3 front shaft along with rear shaft from an E36 325is for the front with no extra modding needed. It was a perfect fit. I got so many usable parts off the Z3 donor. Good luck.

Hey guys, been reading a lot about the LSD swap and I just want to verify one thing.

Swapping a 2.8 m52 and zf transmission this week. While I am at it, I am swapping a 3.73lsd from an e30 325is into my ti.

I plan to take the 318ti output flanges and put them in the e30 diff, then use the 318ti half shafts. Sounds simple enough, will it work?

Thanks

[vwmikel]

Someone else told me you can make the ti half shafts fit by breaking the abs rings off and just going without abs. I think I could live without abs in the rear.

This statement doesn't make any sense. Breaking the tone rings off will not make the axles shorter.

ABS is a very important safety feature. I wouldn't even drive a vehicle without ABS. Maybe on a rally car or track car, but definitely not a passenger vehicle on public roads. You'd be putting everyone at risk.

You make it sound like the outcome would be certain death. They were driving cars before ABS came around so I don't think that's going to happen. But, it is simple to keep the ABS working in this case so I would be sure to do that as it is an important feature.

[dave45056]

You make it sound like the outcome would be certain death. They were driving cars before ABS came around so I don't think that's going to happen. But, it is simple to keep the ABS working in this case so I would be sure to do that as it is an important feature.

My ABS went out on my car a few years back. The back would lock up way before the front which was a little scary. After I fixed it, the breaking is perfect. And I never hear the ABS pump working just the rears end even when braking harder than the times when the rear would lock up without ABS.

So I think it is more dangerous to drive a ti without ABS.

[Zigfried3]

Lol! I notice a distinct improvement in MPG when I drive the car versus my husband, who's a little more aggressive.

[bryan413]

Just put in a LSD this weekend. Some things to note.

#1 - its a bear.

#2 - I don't think the top left bolt interferes as much as the car's bushing hanger. I ending up "modifying" it. I bent it off the diff.

#3 - A small transmission jack would've worked better a jack.

#4 - I didn't have to pound on the car's sheet metal besides the hanger.

[ep1275]

Hope you can help me with this question. I have a 3.73 lsd differential from a e30 325is in a 1995 318ti. It still has the e30 output flanges. I followed the how to article posted by Constant Yu at http://www.emotors.ca/Articles/7.aspx I took the inner cv joint off my own 1988 325is and tried to fit it to the 318ti axle (inner splined section), in order to make a hybrid axle that he describes in the article. The 325is (e30) inner cv joint just spun free on the smaller splines of the 318ti axle shaft. Basically, the inner cv joint from the e30 did not fit on the splines of the 318ti axle. I searched Real OEM, and cross referenced for cars that used the e30 325 axle and I did not find odd parts listings that I may be overlooking.

Also, will the e30 axles fit in the 318ti hubs? Will they just slide in, or am I going to run into spline alignment issues again? My concern is that the splines that go to the rear hubs will not mate up. Again, the the article, which I referenced earlier, stated that he could not swap the e30 axles in directly and needed to make a hybrid axle. Please help.

[cooljess76]

Hope you can help me with this question. I have a 3.73 lsd differential from a e30 325is in a 1995 318ti. It still has the e30 output flanges. I followed the how to article posted by Constant Yu at http://www.emotors.ca/Articles/7.aspx I took the inner cv joint off my own 1988 325is and tried to fit it to the 318ti axle (inner splined section), in order to make a hybrid axle that he describes in the article. The 325is (e30) inner cv joint just spun free on the smaller splines of the 318ti axle shaft. Basically, the inner cv joint from the e30 did not fit on the splines of the 318ti axle. I searched Real OEM, and cross referenced for cars that used the e30 325 axle and I did not find odd parts listings that I may be overlooking.

Also, will the e30 axles fit in the 318ti hubs? Will they just slide in, or am I going to run into spline alignment issues again? My concern is that the splines that go to the rear hubs will not mate up. Again, the the article, which I referenced earlier, stated that he could not swap the e30 axles in directly and needed to make a hybrid axle. Please help.

That guy "Constant Yu" has confused so many people with that writeup. It's full of misinformation. I think he also said that 6cyl e30 axles were longer than the ti axles which is completely false. 6cyl BMW's use medium case diffs while 4cyl BMW's use small case diffs. Medium case diffs are wider than small case diffs which means they require shorter halfshafts(axles). That being said, there's absolutely no reason to swap CV joints between the two halfshafts. If you run a medium case e30 diff, just use e30 halfshafts, period. The splines mate up with the ti hubs perfectly and they are the PROPER length. Ti halfshafts are too long to use with a medium case diff.

[Bloo]

Where there many 318ti`s which came with the LSD diff from the factory?
If it helps, my Compact is 1995.

http://www.ss.lv/msg/lv/transport/spare-parts/bmw/3-series/bbxjln.html

I live in Latvia, and this guy sells this LSD diff. Questions: 1) is this really LSD diff. 2) it is said, that it is small case, and the ratio is 3.45, from e36, so is it a diff which comes from e36 sedan/coupe and not from the compact ? 3) is it possible to take the blocking element from this diff and put it in my?:smile:

[tiFreak]

looks like an LSD to me, 3.45 was the ratio for the 318 with a manual transmission and ti's came with small case diffs, it should bolt right in

[cooljess76]

It is a limited slip diff. You can see the difference here:
http://i198.photobucket.com/albums/aa282/schwarz318ti/differentials.jpg

However, if it's from an e36 coupe or sedan, it will not bolt up to the ti:
http://i135.photobucket.com/albums/q122/cooljess76/diffs.jpg

http://i135.photobucket.com/albums/q122/cooljess76/diffs2.jpg

[mreroc]

Read through this thread and just want to make sure I am reading right...good chance I am not as still learning under the car. I have a 96 auto, so would want to swap for an LSD from an auto; an e30 with a small case sounding like the easiest. Not buying this one, but this is essentially what I'm looking for?: http://www.ebay.com/itm/BMW-e30-e24-e28-325is-4-10-LSD-limited-slip-diff-differential-clean-/330674816525?pt=Motors_Car_Truck_Parts_Accessories&vxp=mtr&hash=item4cfdc1460d

Thanks.

[vwmikel]

Read through this thread and just want to make sure I am reading right...good chance I am not as still learning under the car. I have a 96 auto, so would want to swap for an LSD from an auto; an e30 with a small case sounding like the easiest. Not buying this one, but this is essentially what I'm looking for?: http://www.ebay.com/itm/BMW-e30-e24-e28-325is-4-10-LSD-limited-slip-diff-differential-clean-/330674816525?pt=Motors_Car_Truck_Parts_Accessories&vxp=mtr&hash=item4cfdc1460d

Thanks.

Since it says that was from a 325i, it would be from a 6 cylinder car and therefore a medium case diff. A small case diff would come from a 4 cylinder car.

[mreroc]

Right, right. Thanks for that heads up. Figured I miss something even though the info was right there.

[volgapower]

anyone ever tried the polyurethane diff bush?
i can make solid rubber one, or urethane or whatever.
what are pros and cons?

[spidertri]

Whatever material you use for the diff bushing should also be use in the subframe bushings. Stiff diff bushing with sloppy subframe bushings would probably lead to the diff mount welds tearing.

Randy Forbes does the diff mount repair when it tears on Z3s and he recommends urethane subframe bushings with a stock M coupe diff bushing.

[maverick]

Whatever material you use for the diff bushing should also be use in the subframe bushings. Stiff diff bushing with sloppy subframe bushings would probably lead to the diff mount welds tearing.

Randy Forbes does the diff mount repair when it tears on Z3s and he recommends urethane subframe bushings with a stock M coupe diff bushing.

The above does make sense really as the different levels of movement would likely cause troubles.

My question is this, I got one of the Motorsport finned covers I am planning to use on my 188 diff as soon as I finish it and I bought it used for a very good price with a like new urethane bushing in it already. I was told it was an AKG bushing and it is supposed to be an 80A durometer urethane and I believe it is a purple color which is supposed to be a street compound. I am planning on doing the subframe and swing arm bushings as well and wonder which might be best anyway but am thinking the PowerFlex purple ones, would the be compatable do you think with the diff bushing I have or should I replace that as well?

I wonder if I should use urethane at all and just use stock rubber all around? Is there any better than other stock parts that can be used? Is good urethane better?

I like a taught car and don't mind a bit firmer feel as I am running TC Kline D/A's front and rear with 400lb front and 500lb rear springs so firm but not hard so I like compliant and not stiff. Any suggestions as it looks like I may start this project sooner than later and one other thing is I am likely going to have to tackle most of the work alone so ease is a factor.

Thanks
Dave

[volgapower]

the weld on the floor got torn, welded today...
but both subframe and diff bushes are out of order.
can this lead to vibrations from the rear while accelerating?

[volgapower]

here is part number of my diff...
i found it after removing the cover
4061004301 i think its a ZF part number
but i can not find out what tipe of LSD it is?
clutch, torsen, visco???

and what type of oil it requires?

here is the picture
http://s18.postimage.org/5op9s568p/Image0871.jpg (http://postimage.org/)
image hosting jpeg (http://postimage.org/)

[cooljess76]

here is part number of my diff...
i found it after removing the cover
4061004301 i think its a ZF part number
but i can not find out what tipe of LSD it is?
clutch, torsen, visco???

and what type of oil it requires?

C'mon man. I just posted this IN THIS VERY THREAD a couple weeks ago:

http://i198.photobucket.com/albums/aa282/schwarz318ti/differentials.jpg

75w-90 with LS additive.

[volgapower]

yes but on the lifted car
if i turn one wheel, the second makes no move

on cluch type lsd, both wheels spin same direction...
thats why i am confused

[cooljess76]

yes but on the lifted car
if i turn one wheel, the second makes no move

on cluch type lsd, both wheels spin same direction...
thats why i am confused

It doesn't always work. Are you spinning the wheel forward?

[volgapower]

i tried both directions

[Michael_M]

CoolJess
You mentioned with 6cyl swapped engines people use ZF Tranny? I was somehow planning to swap my engine with M52b28 and I was going to mate it with my current tranny (Getrag), will that be alright? and the propeller shaft should be good? also planning to do 2.93 LSD as I drive a lot on the highway and mainly I use the car as a daily drive than autocrossing!

Any Advices for that?

[Fuzzy Nutbucket]

I believe it "should". I did an S50B30 swap with the same Diff as you (and e30 6cyl. axle half shafts) But i did take my drive shaft in and have it shortend an inch as well, he also balanced it. Still good a few years later.

[cooljess76]

Michael, you'll be fine. The Getrag bolts right up and is more than strong enough to withstand the added torque. You'll definitely want to run a 6cyl clutch and flywheel though.

[Michael_M]

Yea I was planning next time when I replace the clutch to replace it with the 328 one even if I'm ok the the M42 at the moment, just to give me a better grip..

Thanks for the quick answer.. appreciate it!.. I'm dropping the idea of the 2.93 LSD and replacing it with the 3.25 LSD or 3.71 LSD If i'm lucky finding a good deal in any of them!

[killergopher]

What is the production month/year of the 318ti that this is going into?
1995, not sure of month

What type of transmission?
getreg 5 speed

Drive shaft came from what year & model car?
stock 95 318ti driveshaft

Diff. ratio
4.10

Diff. case size
Medium case

Diff. was taken from what year & model car?
taken from an e30 m30, not sure of year

What type of diff. cover?
stock diff cover

Diff. cover was taken from what year & model car?
n/a

Output flanges were from what year & model car?
stock output flanges, they were already on the diff, the kid said he pulled it out of the e30 m and didnt take anything off of the diff just changed the fluid.

Half-shafts were taken from what year & model car?
bought a brand new pair of 89 e30 rear axles

What modifications did you have to do?
had to notch a beam that blocked the diff from mounting To the car. The upper most bolts were hitting the beam. Less than a 1/4 in deep and 6 in long piece was cut out.

Have you had any issues with this combination?
Car runs great, the cv boots seem to rub against the suspension, not sure how to solve that problem yet, thoughts?

Misc. Notes
The stock bolts that connect the axles to the diff were to short for the new axles and diff, the bolts that came with the new axles were to long and to wide to fit through the duel bolt washers (dont know their technical name, sorry) that go between the bolts and the axles. So we had to go to a junk yard and pull axle bolts and duel bolt washers out of a e36 328i. With that hardware we could bolt everything up no problem. Any e36 non m should have the correct hardware.

[samdemange]

hi,here it is my contribution for diff parts
litle case= 168 =4 bolts on flanges
medium case= 188 =6 bolts on flanges
those number corresponding with the diameter of the circlet in those diff
168 are mounting in 316i,318i,320i e30 and 316ti, 318 ti e36
188 in 323i,324td,325i, ix ,M3e30 318tds,323 ti
see board for e30 gear ratio
pic 143 188 3.07 323ti e36 diff
pic 144 188 3.73 325i e30 diff

[Bloo]

Will the LSD from 323ti fit into 318ti (is it straight plug and play) The 323ti LSD is medium case diff, so I consider I will need also 323ti halfshafts, am I right?

[samdemange]

Will the LSD from 323ti fit into 318ti (is it straight plug and play) The 323ti LSD is medium case diff, so I consider I will need also 323ti halfshafts, am I right?
yep u right :smile:
but the 323ti diff dont have a LSD (its a ASC/T system)
and the gear ratio is 3.07 ( too long )
its why i put a 3.73 e30 diff with a LSD on my car :biggrin:

[RBE36]

My diff; late 95 318ti, had to put a thumb size dent in the crossmember, nothing more, for clearance.

Medium case from an 88 325. Gutted it, started over.

4.27 ring and pinion from an auto trans 525i. I refused to pay 1400 for a set of "motorsport" gears when these are a dime a dozen in the euro junkyards.
Bought the whole diff for 150.

Helical M-Z3 center. Ebay. 500 bucks, Nearly new.

M-Z3 Cover

New (not reman) e30 6 cylinder C>V shafts.

Rebuilt with all new bearing, ditched the speed sensor as the shop mixed up the tone rings and didn't know which one went in. After trying 3 different sensors I said screw it.

[96318ticali]

Great info every one. My 97 ti came with an extra diff that is a small case LSD. I swapped it in yesterday. Direct swap, same ratio no install issues. BUT, when I test drove it, I experienced a lot of wheel hop on launch (2500 RPM, dump clutch, smash gas). Is this common? The diff has a polyurethane bushing, suspension is Bilstein HD shocks, H&R sport springs, stock RTAB (new) and polyurethane subframe bushings. The rear tires are not performance (kuhmo Ecsta w/ 600 treadwear rating). This is the way I bought the car. It also came with a set of R compound tires on 16" wheels. It rides/drives great. Any way to eliminate wheel hop?

[e30jake]

I just picked up a 98 with an open diff (I assume it is the stock 3.45.) I have a small case 4.10LSD from an e30 sitting in my basement. I have helped a friend put a medium case in his ti, and did it the proper way with e30 axles. From what I understand, the small case is a direct swap and will fit with the ti axles, correct?

I'm still going back and forth on whether it is worth it, as it is a daily driver and I almost have my e30 back on the road with an s50 to be the fun car. I'm wondering if anyone has input on how drivability is affected with 4.10 gearing. I know my highway rpms will go up, but the car will be used mostly around town anyway. Is first even usable or will I essentially have a 4 speed?

[M GmbH]

I have a question for the gurus. I have a complete rear subframe from a Z3M that has a 3.23 LSD. From what I understand that's higher than what the car has in it now, '98 w/5-spd. I can purchase a 4.10 from a Z3 coupe. Is the 4.10 to much for a 4 Cyl. track car?

[vwmikel]

I have a question for the gurus. I have a complete rear subframe from a Z3M that has a 3.23 LSD. From what I understand that's higher than what the car has in it now, '98 w/5-spd. I can purchase a 4.10 from a Z3 coupe. Is the 4.10 to much for a 4 Cyl. track car?

It would accelerate faster, but would be screaming at high speed. I guess the question is how fast you plan to go?

[M GmbH]

Going to be a dedicated race car. Top speed not as important, getting off the corners hard would be better.

[Kuluvu]

I just picked up a 96' auto... I know, it's an auto, ugh, but it was also practically a steal.

The gentleman I bought it from stated it had a 4.44 LSD, but wasn't sure what it came out of.

Does this sound correct to anybody? it seems awfully low for an auto.

[BRADESTAR]

I just picked up a 96' auto... I know, it's an auto, ugh, but it was also practically a steal.

The gentleman I bought it from stated it had a 4.44 LSD, but wasn't sure what it came out of.

Does this sound correct to anybody? it seems awfully low for an auto.
Yes, that's correct. It came in that there TI stock. A small case

[Alivinglegend]

I just swapped a medium case LSD into my ti, I used a 3.25lsd from a 1984 E28 524td. I used an E30 rear cover and reused my stock ti output shafts. They will work, but they do not fit correctly into the medium case diff, if I had realized they would be this bad I would have done the E30 halfshaft swap. The diff has little rings in it that snap into a grove cut into each output shaft, and to get the ti shafts into the medium diff far enough to work you have to push them past the point where they snap in. There is nothing really holding them into place in this position, but once the diff is in the car and the ti axles are bolted up there physically isn't room for the axles to pull out far enough to cause damage. I don't think the axles have a lot of extra travel in them, but it's hard to tell. I do worry that there is the chance of binding, but again I don't have a way to tell, we will just see how long they last.

Getting the medium diff into the car is tricky too, the vent and top couple bolts on the rear cover are very close to a rear crossmember, and if you don't push the back of the diff into position first it will hit and won't fit. With it all bolted up the tabs that grab the rear mount appear to be in constant contact with the rear cover. I am getting more diff noise in the cabin than before, but I made some other changes at the same time so it might not be just the diff. Exhaust and suspension were replaced too. At some point I'll probably drop the diff again and grind those tabs back so that they have more clearance.

[StoneWheelRacing]

Thanks Living Legend for that summary on your install. Helps alot. I'm researching info to do the same.

Do you (or anyone else) know of anyway to tell the difference between the medium and small case just by seeing the case itself. I know its easily known if you know the model and engine size and possibly cover shape etc... but what about when just seeing the gear case itself? Is the ring gear actually larger in diameter?

Thanks to a CoolJess76 post from wayback I know I need the following;
E24 3.46LSD from a 5 speed 6 cylinder car. (Possibly a bit lower 3.25 from a E24 for a but more top end)
E30 cover, half shafts, output flanges, speed sensor. Any other suggestions?

AND I'm looking to buy all this right now.

[StoneWheelRacing]

Anyone know if I can swap my small case 188mm 3.46 gear set and LSD carrier into a 6 cylinder case? I know whats involved gear wise, just need to know of its possible.

Is there really a large case? I see posts on other sites saying large case and medium case. I suspect they mean the same...

[macilona]

Call Dan at diffsonline.com.......he is a highly regarded specialist in rebuilding bmw differentials. Got my E30 3.23 lsd from him. He would be great source of info to answer your questions.

[ZEK]

Small case - 168MM
Medium case - 188MM
Large case -210MM


Sent from my iPhone using Tapatalk Pro

[StoneWheelRacing]

Thanks folks. My bad, it is a 168mm. ZEK, I know mounts and covers are different by model etc... but how can I quickly tell size (small, med, large) from just looking at the gear case casting itself? People advertise a medium rear but its hard to discern from a picture as its close in shape to the small. I had swapped in an LSD spool/carrier from a '92 coupe we stripped and junked and was hoping (wishing) I could just swap the guts to a Z32.8 or E24 case. Looks like not. The spool went right in. No changes needed for proper backlash and pattern. It was perfect. Doing gear work for quite a while and I never experienced that before. FYI- CoolJess76 (spell) has an all inclusive post from a few years back listing all the swap options for the Ti diff. I can't search by user name or I'd share it here again. P.S. I'd prefer to bite the bullet and source a complete rear subframe and all parts from a ZM. Know of any?

[mb0686]

With it all bolted up the tabs that grab the rear mount appear to be in constant contact with the rear cover. I am getting more diff noise in the cabin than before, but I made some other changes at the same time so it might not be just the diff. Exhaust and suspension were replaced too. At some point I'll probably drop the diff again and grind those tabs back so that they have more clearance.

I just finished a medium case diff swap and ran into the same issue. The steel diff bushing tab towards the front of the car will rub against the side of the wider medium case diff. What I did was just bend the tab with a crescent wrench, rather than grind it. You don't have to bend it much to get it to clear, and this keeps the coating more or less intact. No issues so far.

The diff I used was a 3.64 Torsen LSD from a Z3. Speed sensor is identical to the 318ti so I used the Z3 one.

I used shafts from a 1989 E30 6 cylinder. They fit perfectly, but you have to shim the ABS sensors as has been mentioned previously. I initially used a 5/8" washer ground to fit but it was too thick and gave me ABS issues at low speeds. What worked better was stacking some stainless steel round shims. You will need 18mm I.D. for the sensor and 6mm I.D. for the little hex bolt. I used 4x 0.5mm thick shims, so 2mm thick overall. This was about half the thickness of the 5/8" washer I used at first.

As a side note, I have the standard 3.45 small case open diff and shafts sitting around now if anyone needs them for a project. Located in Northern CA.

[Erazor]

Hi Guys,

I have a Bond Bug special with a BMW 318i LSD fitted, BMW prop coverted into a Quaife reversing gearbox.

BMW E36 318i LSD 2.93

I have to get a ABS ring made up to fit between the prop and diff but cannot find the drilling pattern drawings on the net for the 4 prop bolts.

Does anyone have a mechanical drawing of the flange and bolts please to save me taking it all apart to measure.

https://bondbugzzr1400.co.uk/bondBugassembled2.jpg

https://bondbugzzr1400.co.uk/prop2.jpg

https://bondbugzzr1400.co.uk/bugframepowder5.jpg

[BlastinBlanks]

So I got a 1998 ti with a small case. Just picked me up a z3 3.15 lsd. I’m noticing the the output flange are slightly bigger than the stock 318ti’s also I’ve noticed that the ti’s fit in the new lsd “I think… the felt snugged”but the stubs on them are much shorter than the z3’s. Can someone please tell me if I should be ok? I really don’t wanna modify the cv axles


Sent from my iPhone using Tapatalk