2004 Buick Rainier has progressivley developed a drive train problem. Initially there was a hard thump in the rear end when we had stopped at a light. This happened frequently. The thump was hard enough that my wife asked the women behind her if she had just hit us. Then ocassionally when making right turns into our driveway the vehicle goes into a problem I can only describe as a seizure. I believe it is trying to determine how the AWD should respond. The dealer only trys to drive car around lot and reproduce problems. Had private garage change oil in transfer case and rear differential. Both were black. The differential had very fine metalic flake in the oil. No parts were found to be loose. Source of metalic flaking was not determined. Vehicle has 65,000 miles and has never been used to pull a trailer and has not been driven off raod. Since the oil changes there have been no thumps and no thrashing but there is still a wine or whilling sound. The sound of something loose being spun too fast It is audible when coming to a stop. So far the thrashing only occurred on relativley slow hard right turns. If it returns or occurs at a higher speed I don't know if you could maintain control of the car.
The reason for my real concern. Christmas of 2006 the service engine light came on. The vehicle was immediatley taken to the dealer. The code indicated a transmission problem of some sort the eventually turned out to be a loss of electric to the transmission. ( or so I was told). the car was left with the dealer for the holiday. Unlike me but I made a check of the odomiter. When the vehicle was returned there was an additioanl 200 miles!
The dealer had sent the vehicle to AMCO for service as they don't do transmission work.
I have no idea who drove the car, where it went or for what it was used!!
All of these probles were reported to the dealer several times while still in warranty.
Which way should I go? And, what do you think is wrong with the drive train? Could the wear in the rear differential have caused all the problem?