[moose09876]

One last post just checking to make sure I'm not missing something before spending the big money. My countershaft bearing was bad when I bought my '13 135i, so I swapped in a GS6-53BZ. This transmission has a very low pitched grumble / vibration above 2k RPM, but ONLY on decel, clutch out, in gear, and it doesn't happen all the time. It seems to sometimes be better temporarily if I just thrash it through the gears, but it will come back. It's also not as bad when the trans is cold. There are zero issues if the car is maintaining speed or accelerating. If the vibration is happening and I push in the clutch, it immediately stops.

Anybody have other thoughts?