Help ID this Diff

[71roundie67mgb65spitfire]

Hello everyone,

looking for help identifying this diff that I bought for my 2002. It was sold to me as a 4.11 2002 diff, although the 6 bolt side cover suggests it is likely an e21.

 

no stamping on the drivers side, no S, but there is an LSD in there. I have yet to count the teeth to determine the gear ratio.

 

The biggedt thing I want to know is what parts I will need to rebuild/ reseal it and install in my 2002. Verifying what car it originally came in is the first step.

 

thanks,

Chris 

[tzei]

Yea it's a E21 pumpkin. 

[TobyB]

Yea, it's a later 6- bolt E21 diff.

 

Casting numbers mean... that it was cast.

 

If you want to know what's in it, you need the faint stamped  numbers on the flat on the side of the 

main casting;

but to rebuild it, go to realoem and stuff a 1982 E21 in.  That'll get you the numbers you need.

The bearings for the pinion were available as standard numbers last I bought them, but they're getting harder to find.

clutches and steels are a lot harder these days...

 

t

 

[jgerock]

Remove rear cover to inspect differential carrier for:

1) Proves this in fact is a limited slip version.

2) Rotate ring gear to locate markings from gear manufacturer (there seems to be only 2 that supplied them to BMW: Gleason and Klingenberg, sp.). The BMW service manuals will decode the markings you find.

3) Wipe any lube remnants from bottom of housing to inspect for metal fragments.

[Conserv]

What they said^! 4.11 seems doubtful, unless it came out of a Euro-spec e21, maybe a 316.

 

I’d expect it to be a 3.91 (particularly if it is an LSD) or a 3.64.

 

Regards,

 

Steve

 

[mac]

What you wanted for your '02.  vs.

What you got for your '02. 

 

Ronald Reagan, "Trust but verify".

 

Oops. ......................sorry.

 

Mac. 

 

[71roundie67mgb65spitfire]

Photos of the lsd and stamping.

 

this was a cheap eBay find, so well aware that there will be some figuring out to do. I also know the rarity of the 4.11 and was skeptical when I bought it. 
 

There are no stampings on the side of the diff which is odd. My plan is to add new bearings and seals, then install it with my 245. 4.11 would be amazing, but 3.91 or 3.64 is also fine. 
 

it is missing the front yoke and one of the half shafts, so will have to move the yoke over from my current diff and source some redrilled e21 half shafts for it. 

[mgben]

If changing the front yoke you need to do the whole pinon setting thing. 
@aceandrew article is great but photos lost https://www.bmw2002faq.com/articles/technical-articles/engine-and-drivetrain/strongest-2002-limited-slip-differential-build-r74/page/2/?tab=comments#comment-1604691

[tzei]

Agree. Pinion off, new bearings etc. and if it’s not 4.11 get gears while it’s all apart. Crush washer/tube is already lost bc d/shaft flange is gone. Need someone that has done these diffs before.

 

Limitedslip.de

Is where i got my clutch plates etc.

Edited January 16 by tzei

[jgerock]

Ring gear may be a Gleason brand “H”.  Rotate smaller carrier to find what lockup rating yours originally had (IE “S25” = 25%, “S40” = 40%).

[tzei]

I believe E21’s had only ”S25” units originally. You’ll see if it’s in oe specs when it is disassambled.

[2002iii]

I'll bet money it's a 3.91 LSD out of an e21 320is.

Edited January 16 by 2002iii
Spelling/grammar

[jimk]

3 hours ago, mgben said:

If changing the front yoke you need to do the whole pinon setting thing. 
@aceandrew article is great but photos lost https://www.bmw2002faq.com/articles/technical-articles/engine-and-drivetrain/strongest-2002-limited-slip-differential-build-r74/page/2/?tab=comments#comment-1604691

Photos suddenly reappear2002_Strongest2002LimitedSlipDi.pdf

[visionaut]

[Cabbage Fumes]

I was watching the ebay listing for this, and it clearly stated that it was (and is, H1) a 4.10, so this question is a little weird.

As far as swapping in your old flange, you can't. 02 = coarse spline, e21 = fine spline.

Edited January 17 by Furry Camel
Oy, the humanity!