Hi all,


I've been driving a our 05 XC70 for about a year, purchased with just over 100k, now has 122k. Since I've owned it I have replaced all fluids, timing belt, water pump, spark plugs and all filters. I drained and filled the ATF twice (20k mi ago).


Lately I've been noticing a shudder of sorts sometimes, in 1st gear only. It doesn't do it all the time and it seems to be only after it has been off, the first acceleration after starting, only noticed it hot. After the first shift I don't notice it. Not consistent enough for me to reproduce or predict. It feels like if you were to accelerate and pass over a small patch of ice, a momentary interruption of power, not long enough for revs to increase, just a split second. We're talking light acceleration, not lead footing it. Transmission fluid is at the proper level and looks/smells good.


It also makes an almost imperceptible noise (with no shudder) when pulling away (wheels slightly turned, like pulling out of a parking lot) when it's cold, sounds like if you ran over a man hole cover that rocked back and forth a little. It's always done this since I've owned it and been under the car 100 times looking for anything that would make that noise and have come up empty, wondering now if it's internal. Engine and tranny mounts look good, prop shaft feels good, CV joint boots are all good.


And lastly, last week after 2 hours on the highway getting off the exit it downshifted for no reason (steady throttle, not accelerating) and hung at ~4000 rpms for a few seconds then shifted and has been normal ever since.


Any ideas?


Thanks.

 

I would start with a transmission service and update the tcm software to the latest version

 

It is not a software issue as some scientists here would think. You have two issues:

1.) You need to replace the three transmission solenoids.
2.) You need to replace both drive axles.

 

Thanks for the replies, I'll start doing some research.