BraveHelios

Hey all,

My son just swapped his rear diff on his 01 530i 5 speed. He found lots of info out there about performing the swap on his car... like having to swap the prop shaft flange between the manual diff and the auto diff.

I am thinking about do the same to my 04 545i 6 speed but there is not too much info out there about performing the swap.

There seems to be a good supply of auto diffs on ebay ect... I'm thinking either 3:38's or even 3:46's.

Anyone do this swap? Any top tips or DIY instructions out there?

Thanks!

JuniorB

Swapping these out are pretty straight foward if you ca wrench. All the e60 doffs will bolt up, unless your swapping an m5. The lower 5 cars had a higher gear, like 3.91 which would give you great torque off the line, and should run around 2900 in the upper range depending on your tire size. This works well if your running 19'

BraveHelios

Thanks! I am running aftermarket 18 inch wheels but with stock tire sizes.

I am aware about how the automatic cars have the lower gear ratios. Is there a difference too whether it is a 545 auto or a lower 5 Series with an auto?

I would imagine that only the M5 has the LSD. How difficult a swap would putting an M5 diff in a 545 be?

star69me

hey nice post. I have a 07 550i stock and I want to do a rear diff swap. can you give some tips on what car I need to get it from

ff54976

I have a 550i manual (2.93) diff and want to swap for a higher geared diff.

Can i Swap a 530i rear diff (3.23) on my 550i? meaning does everything bolt up easily or is there ANY modifications that i need to do to make this work?

If you have a better/more cost effective way of doing this please let me know.

Im ok with 3.38 and 3.46 gears as well

JuniorB

Couple things to look for, the 525,528 cars may have the smaller side, not 100% on that. I do know the axles are different in the lower up cars, but on a good note, they also have the higher gear diffs to make up the difference. My 525 rear axles have a smaller outward flange than my 535 acording to real OEM. The 525 did is 3:94 or so. It's one of the highest gear ratio that I've read.

ff54976