replacing 323i 2.93 open diff to e36 m3 3.38 lsd

[joseRoz]

hi,

I have a e36 323i 1997 and I would like to swap my stock 2.93 open diff to e36 M3 3.38 lsd diff for skids\drifting (I am a beginner).
I compared on RealOem site the 2 diff and and as far as I can see there are possibly two differences: the input flange and the output flanges.

Input flange on the m3 has a circular output flange with 6 non symmetrical bolt holes,
while the 2.93 diff has 4 holes, from comparing the pictures it seems it can fit to my 323i but I can't be sure.

Output flanges definitely different because the part number are different.
my 323i open diff is 33131214102 (86mm), and M3 3.38 diff is 33132227265 (94mm).

My main concerns are wether I can swap the outputs on my 323i and insert them into the M3 diff? (I don't know if the thin part of the output flange is the same measurement.
and if the input flange will fit to my 323i or I will need to swap it? (without breaking preload and backlash).


I was looking in the DIY section but couldn't find a tutorial, if there is one please send me.

[flyfishvt]

I see you're in Australia. My comments only apply to the Medium Case LSD. The Euro M3 used a Large Case dif.

As long as both differentials are medium case the following applies. The output flanges pop out easily so you can pop in your 323 flanges. No modifications needed. Most medium case dif input flanges are 4 bolt. In the US only the 95 m3 and a few 96-98 328s used a 6 bolt input flange. Lots of people have successfully swapped out the 6 bolt for a 4 bolt without issue but to be honest you won't know if it was successful for 10,000-20,000 miles. I always recommend getting a dif that came with a 4 bolt since they are so plentiful over here.

[joseRoz]

I see you're in Australia. My comments only apply to the Medium Case LSD. The Euro M3 used a Large Case dif.

As long as both differentials are medium case the following applies. The output flanges pop out easily so you can pop in your 323 flanges. No modifications needed. Most medium case dif input flanges are 4 bolt. In the US only the 95 m3 and a few 96-98 328s used a 6 bolt input flange. Lots of people have successfully swapped out the 6 bolt for a 4 bolt without issue but to be honest you won't know if it was successful for 10,000-20,000 miles. I always recommend getting a dif that came with a 4 bolt since they are so plentiful over here.

thanks foe the comment!
yes both diffs are medium case. The one that I want to order from the US is from s52.
great to hear that I can swap the output flanges, I was worried that the 323 output flange dimple side (spline?) will not fit into the insides of the m3 diff (because the m3 flange is bigger).

about the input flange, all m3 diffs I found on ebay have *C* type input flange, while on the 323i I have got A or B (need to check for sure, probably B type).
Is it suppose to fit (cause its non symmetrical) or this is the 6 bolt version of M3?

what do you think is a fair price to buy 3.38 for?from where do you suggest to order?