E32 750i or E34 M5 LSD SWAPPED INTO E39 540i

I know this has been covered somewhat in previous posts but there are a lot of different answers floating around. I know that this swap involves custom fabrication for mounting the differential and getting the pinion angle right. I have also seen a few different answers to the question regarding the ring gear on E39's. Most are saying that the six cylinder E39's are 188mm and the 8 cylinder 540i's are 210mm? I believe the e32 lsd's and the e34 M5 lsd's are both 210mm. If anyone knows differently please let me know. I am also aware that switching from a 2.81 open diff to a 3.91 or 4.27 would severely decrease gas mileage and increase acceleration as well as lower top speed which with a 2.81 theoretically would be 250mph and with a 4.27 would be 150mph. Any input and information regarding this swap would be greatly appreciated. Thanks,

Jyles

Also is the E39 540i diff considered a medium case diff or a large case?

I hope someone can correctly respond on this as e39 M5 diffs are just so pricey compared to the e32 LSD's. Guess you gotta pay to play, but who doesn't like to get a little dirty to save some bucks.

The other thing I found interesting is that people are using the output flanges off of E32's in place of having to use e39 m5 axles. So theoretically the e32 diff with the e32 output shafts would bolt right up. The issue would be with modifying the drive shaft and making custom mounts for the larger case diff.

I don't have any of those answers, but sounds like a monster of a swap..good luck to you and post your progress on this as I'm sure somewhere down the line, others may want to do the same thing.

Will do

As far as I know I'm the only one with a E34/E32 diff in a E39. The primary reason I went in this direction was the availability of short ratios in the E34/E32 cases(3.64 and 3.91). The low cost of these particular diffs was a bonus. Such short ratios would be undesirable in a 540i like yours. Couple that with the fabrication needed and you'll quickly realize the E39 M5 LSD diff is the best route to take.

In this pic you can see where you would need to fabricate a new front mount

[QUOTE=*****zo;6832100]As far as I know I'm the only one with a E34/E32 diff in a E39. The primary reason I went in this direction was the availability of short ratios in the E34/E32 cases(3.64 and 3.91). The low cost of these particular diffs was a bonus. Such short ratios would be undesirable in a 540i like yours. Couple that with the fabrication needed and you'll quickly realize the E39 M5 LSD diff is the best route to take.





I have the tools and the ability to make any custom mount points. Any pictures or info on the swap you did would be greatly appreciated. Thanks,

Jyles

Originally Posted by m3mods

I have the tools and the ability to make any custom mount points. Any pictures or info on the swap you did would be greatly appreciated. Thanks,
Jyles

I have a semi build thread on bimmerforums under the same username.