Help Support Bigcoupe.com

Diff swap e32 into e24

Post here for mechanical and engine topics such as fuel issues, transmission problems, rough idle, exhaust, electrical issues, etc

Moderators: ron, bfons, GRNSHRK

Post Reply
GazM3
Bigcoupe supporter
Posts: 1697
Joined: Wed Oct 26, 2011 12:55 pm
Location: Melbourne, Australia

Diff swap e32 into e24

Post by GazM3 » Tue Nov 07, 2017 12:42 pm

Hey chaps.

Today has been a good day. Finally got my e24 back on the road since December last year. Mechanic suffered a breakdown so I’ve had to manage car projects directly which takes more time. Retrofitted the 25mm master from 750il, installed new fuel pump, and restored the fuel interceptor computer. It’s good to just drive it again finally.

Anyway. Enough sulking.

My m635csi now runs a dogleg gearbox with a medium case e34 diff running 3.46:1 ratio as the original 3.73 diff was too short. The lsd unit is starting to be ineffective and was contemplating going slighly taller.

I have a spare 3.15:1 e32 750il lsd diff in good condition. I also have my original e24 back plate. This ratio would seem ideal with the dogleg and give me about 2700 rpm @ 100kmh instead of 2950. A big difference is at 160kmh I’ll be doing only about 4300rpm rather than a buzzy 4700. I do also have a set of 3.23:1 large case gearset but it would require opening up the diff and retrofitting the gears. It’s still pretty short geared.

Will the large case fit. (Original diff was 3.73 e24 large case now in my e23)?
BMW’s
74 2002
84 E24 M635csi
86 E23 735i
94 E34 540i/6 SC
97 E36 M3 euro SC

OTHERS
02 Landrover D2 td5
08 Holden Ute 6.0
11 Audi S5

Post Reply

Who is online

Users browsing this forum: No registered users and 10 guests