Thanks again,
RRPhil - that all makes perfect sense.
It also aligns with some further thoughts I've had (probably as you wrote your response!) - I am now thinking that I'm wrong in thinking the "high" valvue shown in ISTA are a problem - I think they simply show an old, worn transmission.
And here's my thinking...
The ISTA values shown above are on a screen labelled "existing adaptation values" but are then listed as "clutch fill pressures". To me, these clutch fill pressure now appear to be actual stored pressure values (in mbar) and not an offset from some nominal value. If so, they are NOT way high - they are all about what you would expect to see in an older transmission.
ZF state the adaptation limits thus: -
These are negative and positive mbar and ms offsets, applied to some nominal base value. I don't think these correlate directly to the values shown in ISTA as I had initially assumed. For one, ISTA is NEVER going to show a negative pressure value!!
This is clearly shown in this screen grab from one of
Mickey Figueroa's great YouTube videos, where the -30mbar offset is shown as being applied to a nominal 600mbar pressure value, giving a stored pressure value of 570mbar.
So what I had assumed were out-of-spec adaptation offset values are in fact likely to be stored pressure values, after the adaptation offset has been applied. I'll dig deep into ISTA and see if I can locate the actual stored offset values but I didn't spot them on the first (or second!) look.
In light of this, I no longer think my adaptations are out-of-spec. Not knowing what the nominal pressure values are for each clutch but assuming that 600mbar might be typical, I think my offsets are still well within the limits stated by ZF. They also align with what both
RRPhil and
Mickey Figueroa indicate, that worn transmissions usually exhibit positive adaption offset values.
So now to figure out what the issue actually is!
*edit* Hang on!! - I missed that clutch D is showing a value of 200mbar - that's -400mbar below the nominal 600mbar value - so that may be worth looking into!