HEEEELLLLLPPPPPPP!!!!!! DIFF DOESNT FIT!!

[752dbl02]

I bought an E21 320is 3.91 LSD for my 75 02 and it bolts in fine, but it seems that the bolt pattern on the flanges of the new diff dosent match up with my CV axles....Solutions??

I have heard that your supposed to be able to change out the flanges from a 02 diff and put them on the E21 diff, is this true???

Please please help, my poor old 02 is my only means of transport, and right now is VERY dysfunctional

[BillWilliams]

the e-21 diff is narrower and has a different bolt pattern.

So you need spacers and someway to make the bolt patterns and size match.

Two ways to do that, switch out the flanges on your diff to 2002 flanges, still need spacers

or

put e-21 CV joints on the inboard side of your half shafts - still need spacers.

Others will chime in on where to buy what and who has what kit.

Make sure when you change the diff fluid you get some friction modifier in there too.

Treat those half shafts to new boots and grease on the out board side too. Now what I have found out is , drum roll please, use some RTV sealant around the cups on the ends of the half shaft/CV joint. Some of them pee grease from there if the cups do not fit perfectly.

[bluedevils]

I may be wrong but I heard that if you use early e21 (77-79?) inboard CV joints you don't need spacers.

[Bill_Riblett]

Have you read the 02FAQ on diffs:

http://www.bmw2002faq.com/content/view/17/32/

[TobyB]

the e-21 diff is narrower and has a different bolt pattern.

The E21 diff is the same width, but the flanges sit in further,

about 1/4"

The early E21 used the same pattern AND the same halfshafts, so you

just need a spacer. And some have gotten away without it, but I never

wanted to try.

The late E21 uses an 8mm bolt in a different pattern and a longer halfshaft.

If you swap 2002 outboard ends onto late E21 shafts, then it all bolts together.

The 76- only diff uses the same style output shafts as the E21, so that you

can pop 'em out of your diff, pop 'em into the E21, bolt up and go.

But only IF you have the kind that pop, not the kind that bolt.

Oh, shit, wait- the early style are held in with a c- clip, so you might have to take your diff apart, pull the clips, and then pop the flanges out.

Then, I dunno if there's room to reinstall the clip, so you MIGHT have

to have your flanges machined with a groove to retain them...

No, none of it's hard, it's just that there are different answers depending

on which parts you get.

t

[felix_666]

there is a thread a few above this one on the same topic, have a read of that.