1997 Bonneville with 84k has occasional launch shudder. Thought the car had a 4t65e, but it actually has a 4t60e under the hood. I know that a bad pressure control solenoid in the 65 causes launch shudder, but what would cause such a thing in a 60?:confused: The car had a fluid change of some sort at about 50k, and I just dropped the pan today, but have not road-tested it yet.

Thanks.

Hmmm... No signs of launch shudder after the pan-drop. Guess it could have been crappy fluid or the level was too high. I took down the 1-2 and 2-3 accumulators and the 1-2 manual accumulator(whatever that means), and found some very crappy old fluid and lots of clutch material. It's amazing how that stuff builds up, and I wonder what the valve body looks like.:grinno:

Thats good.. sometimes the TCC valve gets leaky and allows that CHUGGLE. as it is called..
Clutch material dont sound good.. tho....

GREAT

I don't mean big chunks of clutch material, just the usual(to me anyway) gray dust that floats around in the fluid and settles in the pan. Always seemed to have it every automatic I've had (3), and I don't beat 'em like some people.:grinyes: