Here is the scenario.....changed the rear end on a 2004 Z4 SMG to a 3.46 ratio removed from a 328i. Same housing, except for the cover. No big deal, change the cover and installed perfectly. Now the car seems to be shifting harder into 5th and 6th gear, and down shift from 6th to 5th is hesitant. All mounting points are nice and tight, aswell as the drive axles and drive shaft. Any ideas. My thought is there may be some adaptive driving needed. Trans ECU may be a bit confused in comparison to what it was used to with the original gearing. One last thing...using Redline 75/90 API GL-5 synthetic fluid.

Thanx for the input.

John