Swapping rear axle, sub assembly

[Jimminy]

If starting with a Z4C 3.0 si, is it a straight swap to replace the complete rear sub assembly (diff, axle, breaks, suspension etc) with the one from a Z4m or e46 m3?
Is it possible to mix and match or is it best to do everything that's attached?
Would the wider track give any issues? How much wider is it?
Is there an increased risk of the back end cracking, ive seen something about that somewhere.

This has probably been done to death but I could not find the posts. Cheers guys

 

[srhutch]

What are you trying to achieve?

The axle is narrower in the ///M's hence if you stick 224's on a standard car they stick out further.

If you are after an LSD, probably better to get an MFactory one or similar and swap the internals.

 

[Jimminy]

Thanks, I was thinking about it for the lsd, meatier rear discs would be a bonus (visually) but from what you say adding a lsd sounds like the right move.

 

[JonnyB]

Can you go for this and let me know how you get on?

http://www.birdsauto.com/parts/L8533L85301

 

[srhutch]

Can you go for this and let me know how you get on?

http://www.birdsauto.com/parts/L8533L85301

Perrygunn has just had a quaife diff fitted by birds. Machine Monkey fitted a MFactory diff.

 

[PerryGunn]

Can you go for this and let me know how you get on?

http://www.birdsauto.com/parts/L8533L85301

Perrygunn has just had a quaife diff fitted by birds. Machine Monkey fitted a MFactory diff.

Yep, as Steve said, I had a Quaife fitted by Birds a couple of weeks ago.

The installation thread and my first impressions can be found here

 

[GuidoK]

Thanks, I was thinking about it for the lsd, meatier rear discs would be a bonus (visually) but from what you say adding a lsd sounds like the right move.

You also get a different ratio with the z4m/m3 rear axle. But an axle swap is easier than placing a lsd.
So first think about what you want/want to achieve and who's going to do it.