I took this from my previous post:
I have a automatic 98 Cavalier which has given me no real problems up until now. Lately, my car's been slow to accelerate and it "shudders" when shifting gears. It gets so bad that it will make the car jerk. NAPA suggested adding Shutterguard to my transmission fluid, which I did and it was ok for a day, then back to jerking. I brought it to my mechanic last month and he changed my transmission fuel and filter and said it should be fine. NOPE! Not even a little better. I'm just wondering if I need a whole new transmission or if maybe there's a less expensive solution.
So that's why I took it to the transmission guy. He also said something about the transmission shifting hard because it's cold (my temp gauge is stuck on C). I'm hoping maybe once the temp sensor is replaced, that will fix the problem??