What other cars share our differential?

[Stainless 45]

So while budgeting for a Dinan 3.45 diff for the M3 I came to find out that they no longer offer this ratio, and any back orders have been canceled. Explanation was that BMW Motorsport has dropped this gear set from their lineup. So now I will be shopping around for a used one, or one from another donor M car that shares the same diff as ours. Does anyone know if anything else in the lineup has the same rear differential as the M3? Need more torque to the road but not willing to go as radical as the 3.62. Thanks for any input.

[Arben]

Turner motorsports has 3.45 (and any other choice). No reason to risk it.

[bigjae1976]

I think an F10 M5 shares an upgraded version of the diff.

I do believe the E9X M3 diff uses a 210mm gearset. So, I think, if you can find a 3.45 from an E46 M3 or E39/60 M5...you can change out the R&P.

I'm going to stuff a 4.10 R&P into my E46 M3 and take the 3.62 and see if it fits into my E90 DCT.

[s4one]

Originally Posted by bigjae1976

I think an F10 M5 shares an upgraded version of the diff.

I do believe the E9X M3 diff uses a 210mm gearset. So, I think, if you can find a 3.45 from an E46 M3 or E39/60 M5...you can change out the R&P.

I'm going to stuff a 4.10 R&P into my E46 M3 and take the 3.62 and see if it fits into my E90 DCT.

To do this, can one just swap out the R&P or does this require shimming and other parts? I too have a e46 m3 and want to go to a 4.10

Thanks

[Patrón]

i want to find a 6spd e92m diff and swap it out, so bad...

[bigjae1976]

Originally Posted by s4one

To do this, can one just swap out the R&P or does this require shimming and other parts? I too have a e46 m3 and want to go to a 4.10

Thanks

Depends, you'll need a crush sleeve and maybe some bearings and shims. Mostly small consumables.

Apparently the install a total PIA. You have to get the preload and backlash correct (whatever that is) or else you'll be clunking like crazy and destroy your diff.

[Stainless 45]

Originally Posted by Patrón

i want to find a 6spd e92m diff and swap it out, so bad...

3.85? That would be a bit much for DCT no?

[Patrón]

Originally Posted by Stainless 45

3.85? That would be a bit much for DCT no?

My brother had 4.10s in a e46m and it was awesome.
I had 3.15s in my 95 and the switch to a 3.38 wasn't very noticeable. I've never been anywhere near the redline in 5th. Doubt even on a track redline 6th is pretty fast/hi mph. I think it would be a fun mod.

[surlynkid]

To properly set backlash and pattern, you need a set of setup carrier bearings. You need a tiny torque wrench to set bearing preload. You need all the seals, shims, and the pinion crush sleeve if so equipped. I have done it on Toyota 8.4" and Dana 44 for locking diffs. You need a dial indicator and special grease to check the teeth. This is not a one banana job. Setting up gears is as much art as skill. Even with my background, I would pull my diff and have it set up professionally with a better LSD but probably no R&P swap since I have DCT.