So I have been “limping” along my S6 for some time now, manually shifting and lifting between shifts because the slamming shifts has become overbearing. Over the last year there was a circumstance where the trans slammed 3rd gear near redline, shifting from 2nd. When I say slammed, I mean I thought I blew a CV axle or the engine tore free from the mounts. To my surprise the car still drove nice and smooth under normal loads, still drives normal. This time, a WOT shift from 3rd to 4th caused a missed shift where the tac went to 7k, and then shifted to 4th. No slam or lurch, just a miss…
I can attest the trans was not perfect prior to the tune. I changed the fluid and filter when I pulled the engine, from there symptoms seemed to increase from OK --> BAD, still after the ATF was heated up I was able to shift through gears at WOT with the normal TCU slam we are now used to with the tune.
Slight side step here - In an ideal world I wish for a TCU tune like the Cayenne where it starts out in 2nd nice and sluggish and slow. On the S6 I have to feather the pedal so lightly to have it not jerk the car with so much thrust from 1st to 2nd. If I could put the Gear Selector in Sport to achieve this behavior would be nice so others could drive my car in D.
From some research found this:
Below are my values:
So from the above data, I am not sure if I am out of spec or not. According to the SSP found here there are some blocks out of range. Not sure if these are related to hard coding from the TCU tune or if these are learned adaptations.
Has anyone rebuilt or replace the valve body on these? I also hear Jag/Rover/BMW people discussing a worn out of “separator seal” that seals the trans to the valve body. However I read that my pressures would be much higher if I was loosing pressure at this seal.
Would a log of these measuring blocks show any further detail that may lead to figuring out what is happening here? No stored codes in ECU, ABS, or ECU.