My auto tranny and lsd needs to be replaced and there is a guy in town that has an 86 that he will sell me for a reasonable price (motor isnt to good from what he told me) but the drive train sounded fine. How hard would it be to put the s4 tranny and diff in my 91 s5?

 

ok... so you wanna do a auto to 5-speed swap......... difficulty is in the medium range due to the crossmembers not aligning..... trans will bolt to motor, you'll need a 5-speed n/a starter, driveshaft, pedal assembly, slave cylinder and lines, shifter, flywheel and clutch assembly...... but it can be done fairly easily

 

oh... and the diff isnt hard at all............. i found it easier to swap the whole rear end!

 

well, ill be buying the whole car with everything still in it, so i should just be able to take it out and put it in.

 

Well as far as the trans mount (cross member) goes. You would just use the s4 mount that comes with the car, and you should be just fine. But i suggest that you replace the trans mount's rubber blocks that comes with the car; since those blocks would be worn out. Good luck!!

 

Only other difference is that 5th gear will be a little taller on the 86-87 tranhy over what you had before

 

What do you mean by taller?

 

.711, instead of the 88 and later's .697

 

I did the swap with a S4 drivetrain into a S5 car. If you have any questions just PM me dude.