Help:E32 735iM to E34 535iM Differential swap?

[grave77]

Hi ... I found the ratio I was looking for in a 735iM but the differential measures 1.5 inches longer than mine ... the technicans said it wont fit!! does anyone really knows about it? I wasn't able to get the right ratio to replace the 3.91 I have on my car. if it doesn't fit does anyone knows about the Japanese imported cars and which ones has less ratio on 5 series from 520 to 540i anything between 3.46 to 3.64 ... thanks

[632 Regal]

Hey Grave, the M cars and the 540's used the larger diameter ring gear units in our E34s. I think you can change the brackets to a 540 car and get it to physically fit but you may have other problems such as the input driveshaft is probably different along with the side outputs...It might be possible but would be a lot easier to get the right unit in the first place (which may also need the in/outputs swapped) The bigger unit you will be limited as there isnt a bunch of different ones and you cant use yours (input/output flanges) on it either.

[grave77]

well i noticed that the input flange is bigger by fractions of an inch, but the length was the issue, its that the drive shaft wont fit at the same length. the space now is around 160Cm and the drive shaft is exactly at that length. the 735iM has longer differential gear and longer driveshaft, I might need to shorten my driveshaft to fit in the 735i differential.
what ratios does the 540 use? is there anything less than 3.91? or in the 530i ... anything that would fit in ... also I wish to find a better driveshaft .. this one sux !! thicker one would work better ... I couldnt find the M5 driveshaft ... any suggestions ?