Installed 3.45 LSD today

[L84THSKY]

Hello All

Did the swap today. After getting the diff and half shafts out, we discovered a problem. The E30 flanges did not mate up with the E30 half shafts. Some how the year of the diff, did not match the year of the half shafts. So I said to my friend, " Looks like we gotta try plan B". It was time to test the E30 diff with the 318ti flange and half shaft theory. Will it work or not. I've heard so many stories about problems, and no problems. Here is what happened.

The diff was a pain to get in, but it fit just fine; no modifications period!
The 318ti half shafts and flanges fit fine with no problems. So as it stands, I have a 6 cylinder 3.45 LSD with 318ti flanges and half shafts. That was also with the M-coupe cover installed. I didn't tighten the drain plugs very tight, since I couldn't find the 14mm allen socket. I also need to torque the rear cover down to spec, when I get the correct value.

Took the car for a drive, and all is good.

I also put on the Mini rear muffler hangars;check the picture.

[FATHER]

good job, hey remember repair your spare tire :)

[L84THSKY]

What do you mean repair your spare tire? I just had to let the air out. I always carry an air compressor in my car anyway.

good job, hey remember repair your spare tire :)

[Couverman98682]

Looks nice and clean. Does it drive different since its from a 6 cylinder.

[SporTi]

I am new to the Ti world, but learning quickly. I assume from the rpm that my car spins that stock is 3.90? 4.10? I plan to go dasc eventually and have thought that with the extra power a lower diff might be in order. What was the source for the diff,and what is our normal ratio?

[GDB]

I am new to the Ti world, but learning quickly. I assume from the rpm that my car spins that stock is 3.90? 4.10? I plan to go dasc eventually and have thought that with the extra power a lower diff might be in order. What was the source for the diff,and what is our normal ratio?

Stock is 3.45 for the manuals and 4.44 for the autos.

As for changing out the diff, the cheapest way is to get one out of an E30 (previous generation 3 series) in the ratio of your choice.

[andyman7931]

so all you did was swap the ti flanges to the e30 diff... hmmm... maybe the 3.73 ls diff beckons me from the garage sooner than I thought!

let us know how it holds up over time.

[L84THSKY]

I don't notice anything different driving it. I now have a set of rebuilt halfshafts that cost me over $500.00 that I'm not using. Until if and when I get a supercharger, I probably won't need them. Now I must decide if I should find flanges to fit my halfshafts, or just exchange the halfshafts for ones that mate with my E30 flanges.

The halfshafts were ordered from Circle BMW, and I'm not sure I can return them or even exchange them. So the easiest thing would be to find flanges that mate.

What annoyed me was I was told that all the late model E30 flanges would fit all the halfshafts. I'm gonna take pics of the flanges and halfshafts so the mystery can be solved. I remember ordering the halfshafts to fit a 1991 E30, can't remember if it was a 325I or what. Not sure what year exactly the diff came from.

Another interesting thing was the speedo sensor. The E30 diff had a different style and connector type. I put the 318ti diff sensor in the E30 diff, and it works fine.

Looks nice and clean. Does it drive different since its from a 6 cylinder.

[cali-ti]

realoem shows the same flanges for ALL years of e30 325i. it also shows the same reman'd halfshaft part number (which makes sense), but i know for a fact that there are differences in the actual ones used on the cars (and showed and spoke of the differences i found in my posts and gallery pics). they changed from hex head bolts to torx bolts and they are different lengths, i'm assuming in response to the different thicknesses of the halfshafts where they bolt to the flanges. what's the part number of the flanges you bought? i bought brand new e30 flanges and had no issues with it bolting up to the e30 haflshafts except for the length of the bolts. i'll take a look at the pics when you post them up.

EDIT: and remember you did NOT get an e30 diff!

[stormos]

all i can say is "IT'S ABOUT TIME!!"

[andy]

Interesting - if you can post part numbers or the years of each of the pieces, that would be great. My '88 325 diff + '84 318i halfshafts definitely needed some help...eventually mated them to the ti hubs.

[L84THSKY]

Here are the details.

Halfshaft part# 33211226901

This crosses to:
E30 318i SEDAN
E30 318i CONVERTIBLE
E30 318is COUPE
E30 325i CONVERTIBLE
E30 325i COUPE
E30 325i SEDAN
E30 M3 COUPE
I remember ordering halfshafts for a 1991 325i.


Torx Bolts part# 33211227279
TORX SCREW M10X50 ? from 08/1990 onward

Halfshafts have a 10mm size bolt, as do the flanges.

The difference is in the spacing between adjacent holes.
Shaft = 53mm
Flange = 55mm

That was outside to outside of adjacent holes. I realize it's not true center to center, but it comes out the same when comparing equally.

So, I need to get flanges that mate with my halfshafts.

Interestingly enough, when I read what is written on the inside of the flange, it says on one edge "10" on another "376" and the third looks like "55".

Hard to be sure if it's "55" or "65" or "85". But if it's "55", that confirms what I measured.

So I need 53mm hole spacing.

Here are pics of the two mating faces.



realoem shows the same flanges for ALL years of e30 325i. it also shows the same reman'd halfshaft part number (which makes sense), but i know for a fact that there are differences in the actual ones used on the cars (and showed and spoke of the differences i found in my posts and gallery pics). they changed from hex head bolts to torx bolts and they are different lengths, i'm assuming in response to the different thicknesses of the halfshafts where they bolt to the flanges. what's the part number of the flanges you bought? i bought brand new e30 flanges and had no issues with it bolting up to the e30 haflshafts except for the length of the bolts. i'll take a look at the pics when you post them up.

EDIT: and remember you did NOT get an e30 diff!

[jdehaan]

I'm about to put a 3.64 lsd onto my conversion TI. Its a modified E30 diff i guess that i bought off ebay rebuilt from metrix motorsports. I have no idea how im gonna do it, but it'll get done if its the last thing i do!

[L84THSKY]

Well, it was pretty straight forward. Just ignore all the people who steer you in the wrong direction.

I'm about to put a 3.64 lsd onto my conversion TI. Its a modified E30 diff i guess that i bought off ebay rebuilt from metrix motorsports. I have no idea how im gonna do it, but it'll get done if its the last thing i do!

[cali-ti]

where were the e30 flanges sourced from?

[L84THSKY]

They came with the diff. Bought the diff on Ebay.

where were the e30 flanges sourced from?

[L84THSKY]

I can't decipher that webpage. So is my best solution to buy flanges that were designed for the rebuilt halfshafts I bought? I don't remember telling you what car it came from. If you remember show me where I mentioned it.

Well, it does prove 318ti flanges fit not only E30 diffs, but also 5 and maybe 7 series cars. That's very interesting info.


this page lists the ratios for pretty much every model, but they're not in any particular order: http://www.data.bmrparts.com/bmwparts/326.html

i want to say yours came from a 5 or 7 series (by your own admission when you were buying it) and the page above would seem to confirm that for the 3.46 posi did NOT exist for the e30.

[cali-ti]

i tried to find where you posted the diff you were looking at, but didn't see it handy. did you get it off ebay? if so, still have the item #? if so, you could look and see.

[cossieturbo]

cali-ti... is this what you are looking for? http://cgi.ebay.com/ebaymotors/BMW-Limited-Slip-Differential-LSD-3-64-Rebuilt_W0QQitemZ230007243550QQihZ013QQcategoryZ33731QQssPageNameZWDVWQQrdZ1QQcmdZViewItem

cossieturbo

[cali-ti]

cossie, i'm guessing that would correspond with this one listed on bavarian auto recycling's webpage:

BMW 3.64 Posi diff / Found in a 635csi
1982 1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 1993 BMW 633CSI 2DR ( E24 ) BMW 635CSI 2DR ( E24 ) BMW 325 2DR ( E30 ) BMW 325 4DR ( E30 ) BMW 325E 2DR ( E30 ) BMW 325E 4DR ( E30 ) BMW 325I 2DR ( E30 ) BMW 325I 4DR ( E30 ) BMW 325I CONV ( E30 ) BMW 524TD 4DR ( E28 ) BMW 528E 4DR ( E28 ) BMW 533I 4DR ( E28 ) BMW 535I 4DR ( E28 ) BMW 635CSI 2DR ( E24 ) EURO

seems to be the only one that lists both the E28 and E30. i'm guessing the 5-series will have a diff cover with two mounts (unlike the one mount E30 which is what you would need - or just go with the m-coupe cover), but i don't know that for sure. did you buy already? i'd ask what the diff cover looks like or if you can request, request the one for the E30.

[cali-ti]

L8, my guess would be this one:

BMW 3.46 Posi diff / Found in 528e & 635csi
1982 1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 1993 BMW 528E 4DR ( E28 ) BMW 535I 4DR ( E28 ) BMW 524TD 4DR ( E28 ) BMW 533I 4DR ( E28 ) BMW 633CSI 2DR ( E24 ) BMW 635CSI 2DR ( E24 ) BMW 325 2DR ( E30 ) BMW 325 4DR ( E30 ) BMW 325E 2DR ( E30 ) BMW 325E 4DR ( E30 ) BMW 325I 2DR ( E30 ) BMW 325I 4DR ( E30 ) BMW 325I CONV ( E30 ) BMW 635CSI 2DR ( E24 ) EURO

i believe what this means is that it was only originally used in the 528e and 635csi but that it will work in the models listed. of course, if it fits in the E30, it'll fit in ours. now, what may be interesting for fitment issues, is the front flange which the driveshaft bolts to. i DEFINITELY had fitment issues on the backside of the diff (where the diff cover is) and you say you did not. it would be interesting to compare the size of the front flanges, i bet yours is shorter.

[L84THSKY]

I tried looking for the original rear cover, can't find it in my messy garage. From using REALOEM.COM, it seems the car had to be a E28 series.
Has anyone ever replaced the flange oil seals, the ones just inside the diff? Looks to be easy, but want to be sure. I bought replacement ones, but didn't install them when swapping diffs. I would like to replace seals when I swap halfshafts. Part # 3 and # 9 are what I already bought.



L8, my guess would be this one:



i believe what this means is that it was only originally used in the 528e and 635csi but that it will work in the models listed. of course, if it fits in the E30, it'll fit in ours. now, what may be interesting for fitment issues, is the front flange which the driveshaft bolts to. i DEFINITELY had fitment issues on the backside of the diff (where the diff cover is) and you say you did not. it would be interesting to compare the size of the front flanges, i bet yours is shorter.

[scabzzzz]

so all you did was swap the ti flanges to the e30 diff... hmmm... maybe the 3.73 ls diff beckons me from the garage sooner than I thought!

let us know how it holds up over time.

3.73 feels nice. Short gearing. But not too short. Comfortable on the highway. 5th gear is torquey all the way through. Tops out like 125 or so on my setup

[FATHER]

3.73 feels nice. Short gearing. But not too short. Comfortable on the highway. 5th gear is torquey all the way through. Tops out like 125 or so on my setup

thats is true, i install my 3.73 on saturday and run like 130 with 235/35/19, feeling is cool

[L84THSKY]

Hey Eric

I found the thread about my diff.

http://www.318ti.org/forum/showthread.php?t=6071

Here is the REALOEM listing for that diff.

http://www.realoem.com/bmw/showparts.do?model=4083&mospid=47228&btnr=33_0558&hg=33&fg=05



i tried to find where you posted the diff you were looking at, but didn't see it handy. did you get it off ebay? if so, still have the item #? if so, you could look and see.

[cali-ti]

nice detective work digging that up! :) good that we have all the confirmation on what it came from and such. maybe after i get moved into a new house after breaking up with the girlfriend i'll have some time to do a proper knowledgebase article on diff swaps.

[L84THSKY]

Eric

Did you see the videos from the meet we had in Braintree Mass? You can see my LSD in action.



nice detective work digging that up! :) good that we have all the confirmation on what it came from and such. maybe after i get moved into a new house after breaking up with the girlfriend i'll have some time to do a proper knowledgebase article on diff swaps.

[L84THSKY]

Put the new E30 flanges and reman E30 halfshafts on today. Went in easier than the Ti flanges and halfshafts. I may have damaged the ABS sensors, since I forgot to remove them as I tapped in the shafts. Maybe they are OK, no ABS light on on my dashboard.

[FATHER]

Because you change the flange to a e30, i still use the Ti flanges and half shalf without problems???

[L84THSKY]

Is that a question or an answer? Are you referring to the ABS issue or the E30 flanges?

Because you change the flange to a e30, i still use the Ti flanges and half shalf without problems???

[FATHER]

Sorry, my bad, that is a question, i install the e30 3.73 diff without issues using my stock flanges and halfshaft, so why you need to use the e30 parts, i think is tha same. i know the e30 half shatf and flanges are more strong but our car no have much hp also if is supercharger.

[L84THSKY]

Well, I installed the E28 diff with stock flanges and halfshafts and it fit fine too. That combination was debated forever, but I got it to work. You probably should upgrade the flanges and halfshafts at some point. In your case, you are supercharged, and that is a very important reason to upgrade.

I bought the E30 halfshafts, and had the wrong flanges. So it made more sense to buy the correct flanges, and do a complete swap. Now, I'm ready for some serious power increases.

Sorry, my bad, that is a question, i install the e30 3.73 diff without issues using my stock flanges and halfshaft, so why you need to use the e30 parts, i think is tha same. i know the e30 half shatf and flanges are more strong but our car no have much hp also if is supercharger.

[mooseheadm5]

A quick perusal of this thread tells me that you bought a diff that came from a an E24 6 series or possibly an E23 7 series. E28s had the same size diff case as E30 6cyl/E23/E24 (except for the M5 which had the large case diff) and none had that gear ratio. You can use any E28/23/24 medium case diff provided you swap to E30 output flanges (they pop right in) and E30 or ti 6cyl rear cover with one exception. The 1982 528e is an oddball 2.93. Don't use one of those.
-Paul

[FATHER]

why?!?!?!

[L84THSKY]

If you jump through the thread, you will see that I found my original thread on this subject. It came from a 528E, and it was an E28 diff.

A quick perusal of this thread tells me that you bought a diff that came from a an E24 6 series or possibly an E23 7 series. E28s had the same size diff case as E30 6cyl/E23/E24 (except for the M5 which had the large case diff) and none had that gear ratio. You can use any E28/23/24 medium case diff provided you swap to E30 output flanges (they pop right in) and E30 or ti 6cyl rear cover with one exception. The 1982 528e is an oddball 2.93. Don't use one of those.
-Paul

[mooseheadm5]

My bad. The 1988 super eta 528e automatic had a 3.46. Good ratio. The 635csi was the only other car that came with that ratio (officially.)
-Paul

Also all 735i.