Hello everyone, I have a 1998 Lumina with 82k miles that runs like a top with one exception: the transmission is a little wonky. The shift from 2nd to 3rd gear is too hard, especially under hard acceleration, and when I come to a rolling stop and press down on the gas again, sometimes the transmission will take a half of a second to engage. If I accelerate too fast while rolling slowly (maybe 3-5 mph), that lag will cause the car to jerk when the trans does catch, and if I stomp on the gas and hold it through the 2-3 shift, it shifts way too hard. I don't do this often, but this indicates the presence of problems that will only get worse if they're not addressed.

I've rebuilt engines, replaced valve bodies, and done just about everything else to a car that you can do, but I don't know much about transmissions. I'm looking for an idea of what the problem with my transmission is and how difficult it would be to fix. My guess is that there's an issue with the valve body or one of the solenoids, but I don't want to open up the transmission without being reasonably certain that I'm replacing the correct part.

Any thoughts?

 

Have you done a filter and transmission fluid change? Modulator could also be the cause.

 

Yeah, fluid and filter was the first thing I did. What's the modulator?

 

Nevermind, I just spend half an hour reading about automatic transmissions. Thanks for the tip, I'm gonna check the modulator today.