Ok, I'm confused. I thought there was no difference between the two tranny's except for, perhaps, the mount that bolts onto the tranny that in turn is what you attach the cross member to. I know the S5 mount can be unbolted and exact fit onto a S4 Tranny as far as NA's are concerned.

So, question on the table, exactly what makes the S4 and S5 Tranny's different that they would have different part numbers?

 

5th gear mostly...

I have heard unconfirmed rumor that the M50N (S4 'vert and S5 coupes and 'verts) used slightly stronger syncros and gears, over the M582 (found on all the non-auto tranny, non turbo S4 coupes), but I have never been able to confirm that with anyone.

Maybe someone that has pulled apart a couple of these enough to know the difference can confirm it.

 

as far as i remember the synchros are the same part numbers thru the years. there are small differences, like the 89's have that barrel shaped thing added to the mainshaft

mike

 

Is this true for either NA or TII tranny's?

I remember the rebuilder at Anaheim Gear saying something about that thing, but can't remember what the merit was of it being there.

 

Gear Spacing is different between S4 and S5. By this, I mean that the space between the rows while shifting (1-2, 3-4, 5-R) is different. S4 on the left, S5 on the right.