2005 S80 T6 Transmission slips in 1st after a stop

[shailey]

HI,

My transmission is slipping when I accelerate from a stop light. I press the gas pedal, the engine revs up about 500 rpm, the transmission sort of "clunks" into gear and off we go after about a half-second. This happens periodically - maybe once every twenty starts on average. It may be fine for a couple of weeks, then does it's slip-clunk-go routine maybe 3 starts out of five for a day or two. Otherwise, the transmission seems to operate normally.

Transmission fluid and filter were changed at about 115k miles. It displayed this behavior frequently after the fluid and filter change, but not before. I lived with it for a few weeks after the fluid change and the bad behavior stopped happening. The slip-clunk-go behavior didn't occur for about a year or 20k miles or so. It's back now and is beginning to get me angry. Current mileage is about 140k. As far as I know, the fluid used for the change was Dextron III.

I'm aware of the horror stories about the GM POS 4T65-GT that Volvo specified for this model and if I had done enough homework, I would never have bought a T6. I haven't taken the car to anyone for analysis of the problem. This acts like a different problem than the 1 to 2 shift flare and the 3 to 4 shift flare that I've read so much about.

Has anyone experienced similar behavior? If so, what did you do about it?

[draser]

One thing to check is type of fluid recommended for your car, that's in your user manual. I know on my car they only recommend a specific fluid, so there's a chance Dexron is not good enough.

[matt5112]

Dexron is the correct fluid.

Could be this:

http://tripleedgeperformance.com/No-Forward-Cold.html

But as any transmission shop will tell you, you need a rebuild as well.

[draser]

I believe your car is a little young to have that serious a tranny wear, and you noticed this problem after fluid change. For peace of mind, I'd do another fluid change.