Lets talk rear ends.

[M3TA5IN]

I am curious to please my hunger for knowledge and ideas.

I am mainly familiar with straight axle rear ends like Dana 60s, 44s, ford 8.8s etc. Somewhat on ford 9inchs too.

Can someone tell me or show how most BMW rear ends are laid out? From what I have seen I think it is like a 9inch rear end where the ring, pinion and all that fancy witch craft that goes on inside there is one piece and removes from the axle housing?

Also, what are common ratios for BMWs? 3.15 to 3.65 (M3). I am more familiar with trying to get crawl ratios lower buy using like a 4.56 to 5.13. Essentially though if I wanted faster acceleration I would want to go from a 3.15 to a deeper gear correct? Or am I completely wrong?

Also are the diffs interchangeable? How are BMW rear ends categorized by part? Does a e46 330i have the same rear end as a e46 M3 and just different gearing or are they completely different? Same as e9x to e9x M3?

This doesnt seem to be a topic that is discussed a lot on BMWs. Ive found little information on track forums, but not much else.

[danewilson77]

Our layout....

[M3TA5IN]

Our layout....

Thanks Dane.

[mimalmo]

I like 'em round and a little juicy...