Looking for a new differential...

[mrnine]

You can see my previous posts in this area, but I just found out that my diff is trashed in my 1998 318ti. Clicking and clanking in the rear led me to drain the fluid from the diff and found gear fragments. This puts me in the market for a new one. I'm a little nervous about this predicament. I have access to another vehicle so I'm not in a total bind, but I guess I'm not really sure of my options.

1) Find an E30 diff and put it in. My only thing on this is all the posts regarding this make it sound like a real PITA and I've still never found anywhere to pick up the output shafts. I suppose all the other stuff you'll need is avalable out there somewhere. I'm reasonably mechanically inclined and have a friend with a lift and better tools than I but this doesn't sound fun.

2) Find an e36 LSD from a ti or a z3. This sounds next to impossible. It doesn't seem there were many of these out there. If anyone can help me out or sell me one, maybe you can contact me offline. Not getting my hopes up though.

3) Find a non-LSD small-case differential to install. I sure can't imagine going this route just because if the thing is already out then I certainly should take the opportunity for a performance upgrade. I really am not in a position to spend a fortune here but I'm pretty much between a rock and a hard place I guess.

Any insight or advice?

[mrnine]

Okay, so...

I made some phone calls and think that I've found a 3.45 (3.46?) locking E36 318ti differential. The asking price is $325 plus shipping, which seems relatively reasonable.

I had thought about going with a higher ratio like 3.73 but to tell you the truth, I do some highway driving and am just a bit worried about the higher rpm's in the 70-80mph range, though admittedly I'm tempted by the in town boost the higher ratio would offer.

I also had thought about an E30 swap out, but I hate to go through the trouble of the half shaft replacement.

Am I correct to think that this is probably the easiest, best route for me to take. My #1 priority is getting my car back on the road. It seems that I would get a slight performance upgrade going from a 3.45 open to a 3.45 locking, though I realize I won't get the boost I'd get from a higher ratio.

Those of you who have experienced it...will I regret not going with a higher ratio?

[cali-ti]

what e36 is it from? it must be from a ti or 4-cyl z3 for the diff cover to be correct. if it is, that price seems pretty reasonable (since they're harder to source).

[mrnine]

They claim it's from a ti and that it's a locker and it has a 90-day warranty. I was a bit surprised to find one in the first place. It has like 100k miles.

I've recently seen some E30 half shafts reasonably priced but I swear all the discussions on this topic make it seem like too much of a PITA. I've had a 1967 Impala ragtop torn apart in my garage all winter and almost have it back together. I'm a bit nervous about embarking on another major car project in the garage.

A straight-up LSD diff swap seems tempting.

[pdxmotorhead]

The diff swap is < a 3 hour job the first time around.

Heck I change them at the track in 10 to 15 minutes.
I LOVE air tools. :)

Dave

[stormos]

get a kaaz 1.5/2 way diff! excellent for some sideways action!!

[bullmand]

I've always wanted a Quaife differential. They don't show the part anymore on the US site, but the UK site still shows it. The part number is QDF6N. Koala Motorsport is one of their distributors here and they may have more info. FYI, if you can get a hold of one of these it will be significantly more expensive than most other options. Good luck.

[stormos]

kaaz is around £600 i believe. problem being since you guys use USD, it's a shiat exchange rate...

[mrnine]

Dang, pdxmotorhead...I wish Portland was closer to Ohio. Why, to do the swap for me, I'd give you all the beer you could drink in the 10-15 minutes it took to do the job! :)

Seriously though...is there any critical advice for me here? I'm going to do this next week hopefully at my friend's shop with a lift and air tools. Probably overkill but it certainly seems it should get the job done in less time.

What parts should I have at the ready to replace while I'm in there? I've found all sorts of posts (obviously) on the E30 swap, but remember this is just a simple E36 diff swap out. Similarly, I found torque settings for bolts on the E30 but not an E36.

If you were me, would you pop off the rear cover on the purchased diff, just to make sure everything inside was hunky dorey? If so, I reckon I should have a new gasket ready? Anyone got a part number?

Oops...one more thing: Redline 75W90 or Redline 75W90 No Slip?

[pdxmotorhead]

I would definately pop the cover, just to wipe it out and inspect the unit.
DO NOT USE SOLVENT OR ANY CLEANERS INSIDE, just wipe out
with clean shop rags. You can use a little clean lube to assist on stubborn
deposits, or use a rag soaked in break clean to work small spots out.
Too much cleaner will ruin the lube when you put it back together.

Refill with quality synthetic. (DOn't overfill it will trash the axle seals.)

Only use air tools for taking things apart. Torque everything else
with a decent torque wrench when re-assembling.

Use the right wrenches for the hex heads on the CV's its WORTH
the bucks to buy a set. (the bolts can cost more than the wrenches....)

Look before you remove, often service manuals require steps
you don't need, they assume you have a lift and lots of other tools.

You might consider replacing the flex joint in the drive shaft while
your in there, Unless the existing one is perfect. No cracks and
not brittle feeling.

Good Luck
Dave

[cali-ti]

i would suggest the following:
#06 GASKET ASBESTOS FREE Qty 1 PN:33-11-1-210-428 $2.86
http://www.realoem.com/bmw/diagrams/i/l/222.png
#15 SELF-LOCKING HEX NUT (M10) Qty 4 PN:07129964672 $0.30/ea
http://www.realoem.com/bmw/diagrams/m/c/10.png
hi-temp gasket sealant (eg: permatex high-tack or super high-tack gasket sealant in a spray can) for putting the new paper gasket on the diff

[mrnine]

Someone on this list also mentioned at some point that the bolts that connect the differential to the driveshaft are a one-time use only sort of thing. Is that the case? if so, I should pick those up and I can't seem to sort my way through the diagram to identify which ones they are.

[cali-ti]

#15 SELF-LOCKING HEX NUT (M10) Qty 4 PN:07129964672 $0.30/ea

shown in the second diagram above.

[mrnine]

So...I received a differential today. Found a decent deal at $450 shipped to my door for a 3.45 LSD.

However...upon inspecting it, there's no S on the tag. Looks like it says "345N5??"

Some people on this list have said that you can confirm by turning one wheel. If the other wheel goes same direction, it's LSD. If it goes other direction, it's open. However, some with LSD have disputed that this is the case.

Is there a way to tell whether it's open or LSD by opening the case? Is there anything else I can do here to figure it out? Because right now I'm inclined to think that I may be either sending it back or negotiating about $200 off the price.

[DustenT]

Some people on this list have said that you can confirm by turning one wheel. If the other wheel goes same direction, it's LSD. If it goes other direction, it's open. However, some with LSD have disputed that this is the case.


They will spin the same direction if it's an 3.45 LSD.

[mrnine]

Alright. I just sent a message to my dude saying I want another part. Thx.

[96cali]

btw there is a write up in the notebook section here on swapping in an LSD.