[335iSSA]

I had my Quaife installed this past week and have this same grumbling noise as well. It does not occur in low gears at a moderate throttle but when riding down the highway and application of part throttle it is very pronounced. Like the OP it occurs at various speeds when throttle is applied at low RPMs.

No apparent whining from improper backlash.

Car is a 1/2007 build AT. Unlike the newer pumpkins which are smaller, the shop said it went in w/o requiring any material being removed. Redline N/S Fluid.

I taking it to the shop on Monday morning to get their thoughts. No one else have this issue?