diff compatibility

[moalaska]

I have a 87 924s, I'm fairly confident it has an lsd the thing goes through deep snow and ice better than front wheel drive cars and both tires seem to put power down. My 87 turbo I. the other hand can't go through 0 inches snow downhill while pushing it. What is compatibility if I were to do a diff swap?? Anypros cons if it is compatible??

[kevingross]

The LSD can be swapped between the two transmissions, it is the same. There were three versions (roughly speaking) of the LSD used during the lifetime of the 924S / 944 series cars:
- original version with welded-on ring gear mount flange
- single piece case (no weld) and improved material: type GGG steel
- late Turbo S (AOR) version with thicker clutch disks, moly coated cross shafts, and in some units moly-coated small spider gear teeth

The 87 924S and 87 944 Turbo would have the second version, in all likelihood. Swapping between the gearboxes requires reestablishing differential carrier bearing preload and ring-to-pinion backlash -- you cannot skip this step unless you're okay with grenading the gearbox.

[944 Ecology]

+1

Listen to Kevin! He knows his stuff!

[kevingross]

Aw, shucks! Ty, George.