bmwe21.net forums

I picked up a 3.45 lsd from an e36 318i today at pick and pull for $75. I'm wondering if it's possible to swap the lsd internals into my e21 diff case. They're both 168mm diffs so I'm guessing it would work, but I couldn't find any positive confirmation by searching. Has anyone tried this?

Let us know how you get on? I think Jason323 has swapped some diff internals, or at least knows a bit more on the subject? You could ask on e21 Legion too?

Should be able to do it. Use the E21 casing, crown wheel and pinoin parts. just fit the E21 crownwheel to the LSD and fit into the E21 case. Would be worth checking the clearances once built up using some engineers blue.

Ben

I've been trying to do this too. Crownwheel fits the LSD and it has the same overall dimensions as the free diff that came out, but I can't get the assy to enter the case. Any tips from anyone??

Mark

What exacly is preventing it from entering the case? How tight is the clearance?

Any other suggestions?

Markw wrote:I've been trying to do this too. Crownwheel fits the LSD and it has the same overall dimensions as the free diff that came out, but I can't get the assy to enter the case. Any tips from anyone??

Mark

I remember mine being tight to get through the opening. Lots of wriggling and cursing but eventually it went in. Removing the bearings should help then press them back on throught the driveshaft holes?

Ben

whats the maximim torque rating of the e36 diff? is it more than the e21 or the same?

240/250 ft/lbs iirc. I might be wrong tho - and often am.

Duracel79 wrote: I remember mine being tight to get through the opening. Lots of wriggling and cursing but eventually it went in.

nudge nudge, wink wink, say no more.

Duracel79 wrote:

Markw wrote:I've been trying to do this too. Crownwheel fits the LSD and it has the same overall dimensions as the free diff that came out, but I can't get the assy to enter the case. Any tips from anyone??

Mark

I remember mine being tight to get through the opening. Lots of wriggling and cursing but eventually it went in. Removing the bearings should help then press them back on throught the driveshaft holes?

Ben

It fits OK with the bearings removed, but I had to destroy them to get them off. Made a simple job VERY expensive. Also the manual recommends initial setting up without the pinion to get the bearing preload right. Pinion won't come off with diff in situ. Back to square one!

Looks like I'll have to set it up "by eye" like in the old days. It'll either clonk or whine. Ho hum......

Mark

Remove lid with bearing on. Put in LSD element and screw that lid back on. That how I did. Otherwise everything works just fine.

For reference...

http://forums.bimmerforums.com/forum/sh ... ?t=1565138

i just ginded a litte bit away from the sides of the casing to let it rotate into place used the 3.91 ratio crown wheel and pinion matched the correct bearing races. i used one of the e36(2.0mm) shims on the left(crown wheel) side, had to drill a few more holes and an e21 (1.7mm) shim in the right hand side im no expert but the back lash seems ok the unit is tight within the bearings the gears are meshing with a very small amount of backlash is you can just about feel the movement and the diff is still dry (no LSD oil yet) i replaced all the seals my local hydraulic man got them for me very reasonable

all this trouble and effort, and for what? just weld up an open diff. its a compromise yes, but the shortcomings are few.
try it! personally i still smile when i have to turn a tight corner sencibily. but then i can step it out on a roundabout safe in the knowledge i have complete predictability on what the cars going to do.

you do your first doughnut........ you'll never go back to an lsd with 25% lock up.

plus welding it is free!