335is vs. E9x manuals

[carenthuziast]

Both have 6 speeds. Is the design of the transmissions the same for these two vehicles?

[roastbeef]

no.

[pbonsalb]

I think it is. Both are ZF GS6-53 and rated at the same torque capacity, but one has a bell housing for a V8 and one for the I6. I am also not sure whether the input shafts and clutches vary. You probably cannot interchange without major work that is not cost effective. Maybe the GS6-53 from the other late model V8 cars fits better?

[carenthuziast]

I’m not looking to swap trannies. Just wondering if they’re different especially since the M engine delivers more power and is advertised as having a heavy duty clutch.

[pbonsalb]

Same torque rating. It’s the torque that matters and the 135/335/535 actually have more torque. But this sane trans was also used on the V10 M5 and M6 that make more torque and also on the twin turbo V8 in the later M5 and M6 — actually exceeding its rated torque so the rating is actually low. I am thinking about putting one in my turbo 99M3 that makes about 600 lbs rwtq.

[ec_E92]

Originally Posted by carenthuziast

I’m not looking to swap trannies. Just wondering if they’re different especially since the M engine delivers more power and is advertised as having a heavy duty clutch.

Torque rating plays a much bigger factor than horsepower.

[pbonsalb]

In the model GS6-53, the 53 stands for 530 Newton Meters, which is 391 lbs. That is the official torque rating. Compare to older GS6-37 used on E46 330i and some later M54 and N52 cars — 370 NM rating. But these ratings seem to be under rated because BMW used the GS6-53 trans on the twin turbo M5 and M6 that made 500+ lbs.