955 Transfer Case Problems? Symptoms?
09-03-2023, 10:53 PM
#1
955 Transfer Case Problems? Symptoms?
I have some ongoing shifting problems with my 2004 CTT.
Replacing the valve body cured some of this and made the car significantly more drivable, however there are still some issues that remain.
The main symptoms I've had are a clunk going from 3rd to 2nd which happens fairly consistently. Also, very occasionally it'll have a really nasty 'bang' downshift from 5th to 4th where the car lurches violently.
I just had the fluid changed again and initially it was fine and drove about the same as before, but last night it had some very nasty shifting behaviour between 2nd and 3rd that was similar to how it shifted prior to the new valve body.
There is also a high pitched whining noise which increases relative to RPM. Initially I thought this was the transmission, however now I believe it is either an accessory like the power steering pump, or the transfer case.
Have 955 transfer cases had many issues historically, and if so, how do those issues normally present themselves?
I should mention that the car has just over 200,000 miles on the clock so it is getting pretty high up there now. Maybe the clutch packs and other transmission internals are just worn out? Although these issues seem very much like a valve body or TC symptom, not what I would expect from internal gearbox issues.
Any ideas or help diagnosing this would be massively appreciated.
Replacing the valve body cured some of this and made the car significantly more drivable, however there are still some issues that remain.
The main symptoms I've had are a clunk going from 3rd to 2nd which happens fairly consistently. Also, very occasionally it'll have a really nasty 'bang' downshift from 5th to 4th where the car lurches violently.
I just had the fluid changed again and initially it was fine and drove about the same as before, but last night it had some very nasty shifting behaviour between 2nd and 3rd that was similar to how it shifted prior to the new valve body.
There is also a high pitched whining noise which increases relative to RPM. Initially I thought this was the transmission, however now I believe it is either an accessory like the power steering pump, or the transfer case.
Have 955 transfer cases had many issues historically, and if so, how do those issues normally present themselves?
I should mention that the car has just over 200,000 miles on the clock so it is getting pretty high up there now. Maybe the clutch packs and other transmission internals are just worn out? Although these issues seem very much like a valve body or TC symptom, not what I would expect from internal gearbox issues.
Any ideas or help diagnosing this would be massively appreciated.
09-04-2023, 04:13 PM
#2
It sounds like there are still some valve body issues. Was the valve body rebuilt or new from Porsche? If rebuilt, who did the work? I had some problems with a rebuilt valve body from a reputable vendor and had to send it back twice before it was resolved.
09-04-2023, 11:22 PM
#3
