Bmw X5 E53 Rear differential on M3 E46

[romano21]

hello ! have my M3 E46 since 10 year ago.
i'm in love for it but my lsd is totally destroy since many year. it make a very loud noise when i shift gear or turn left or right.

after a lot of research for a m5 e34 3.91 big crankcase bridge. it seems rarer than adamantium.
I discovered that the X5 E53 3.0D Have 3.91 big case differential.

I can't find much information
Has anyone ever tried mounting the internal X5 IN m3 e46 case?

[Sharocks]

Apparently it fits but I've never seen it done in the US.

[jbfrancis3]

I could certainly be missing something but a quick google shows the case- and cover-mounting points completely different. If you're talking switching in the innards between the two then it certainly couldn't be worth the time and effort.

I must be missing something...

[Nihilation]

May be able to just swap over the E46 M3 differential cover and reinstall?

[Str8f4c3]

Both the X5 4.6is and 4.8is also use 3.91 Large Diffs. May as well just pull the the ring and pinion and swap into the m3 diff, rebuild/replace the lsd and refresh bearings and races, etc. My .02 from the research I've done on the subject.

[S54B32]

anyone have done this? I mean not only from research? Would be a good/cheap source for 3.91 ratio.

[bigjae46]

If its a type 215 diff, the R&P will not work in a large case diff. All of the large case diff internals are interchangeable across the chassis specific case.

Here's a list...

E24 M6
E24 633 CSi
E24 63 5CSi
E28 M5
E32 750iL
E34 M5
E36 M3 (Euro Only)
E39 M5
E46 M3

I think select E34 535s or 540s have the large case diff.