Yesterday, while driving about 40 mph, when I tried to accelerate, the trans acted like it was in neutral--no drive, no reverse. There was no noise--it acted like I shifted to neutral. Car has 166,000 miles, but I've only had it two years, so don't know the previous history, but suspect the trans was rebuilt at least once.
Had the car towed to our local transmission shop. Tech says $2,300 for rebuild with a two year, 24,000 mile warranty. He has done others like this and suspects the converter failed. In his opinion, the small torque converter is the weak point with these GXP transmissions. They have an Impala there right now with the identical drive train and similar failure.
I plan to go ahead with the rebuild, but would like to hear if any of you have info that would help prevent this from recurring.