occasional rev flare from 4th to 5th gear, time for a tranny fluid change?

[Dino Roussetos]

Hi there - My 2005 Cayenne S is running great. On occasion though I notice 4th gear trying to find itself especially if I step on the gas pedal and it's time to go into 5th it will flare its revs up then I let off the gas and it settles into 5th. I don't think the tranny fluid has been changed yet although the vehicle does have 190K miles (305K kms). I have been told by Porsche that changing the fluid might do more harm than good. I am wondering why they wouldn't recommend a fluid change which might help this 4th-5th gear occasional flare. I was hoping to get some input from you kind folks. Many thanks!

[Dino Roussetos]

personally, I don't think there's any harm in performing a drain and fill...except on the pocket book.

[voodoocat]

Transmission fluid and filter change is way overdue. It is not a lifetime fluid.