Transmission Prob-Any Ideas Where to Start?

'00 Grand Am GT1, auto trans., with 25K miles having gear shifting issues. Was driving car after 1mo storage period, and it was fine until almost home. Suddenly, car had a very jerky shift from 1rst to 2nd gear. After a few minutes, the shift from 1st to 2nd smoothed out and putting the car into drive or reverse would cause a jerk. Going to check trannie fluid in daylight tomorrow. Any other suggestions because I am very low on cash, and need to avoid repair costs if I can. TIA!

Purchase a new filter kit from a parts place and change the fluid and filter. Then replace part of the fluid with either a bottle of Lucas trans. treatment or Sea Foam trans. treatment. This should free up the sticking valves in the transmission and eliminate the problems you are having.

Still haven't checked the fluid, but thanks GTP Dad for your advice. I will get around to it. (Got kids, husband on disability, a job, and house to deal with first-LOL.) Put the car in the garage and haven't looked at it since, but I did notice that when the car is cool and hasn't been driven around all day, it doesn't jerk when changing gears. I will update once I have some info for other people's knowledge, in case they are having the same problem.

If the fluid change and SeaFoam doesn't work, I'd look into getting a new Pressure Control Solenoid. The original equipment Delphi PCS is notorious for wearing out early on GM front drive transmissions.

As with the other post for trans problems, guess work should not be a practice here. A trans capable scanner will allow someone to see trans solenoid and controls activity and/or codes, to determine the real problem.

As with the other post for trans problems, guess work should not be a practice here. A trans capable scanner will allow someone to see trans solenoid and controls activity and/or codes, to determine the real problem.

Unless you tap into the transmission to read torque signal or line pressure while you're commanding various PCS currents, you can't diagnose a bad PCS in the transmission, and even if you do tap those pressures, there's a chance that the TS valve or main regulator themselves could be bad instead of the PCS. So, for the symptoms mentioned, the PCS is about the next least expensive ($59.00 if you do it yourself) and easiest component to replace, and they DO have a serious design flaw in that the soft steel armature wears quickly where it rubs against the hard steel bearing (http://www.automotiveforums.com/vbulletin/showthread.php?t=398499&highlight=pcs). There could be other things wrong with the transmission for sure, but for a guy with a DIY spirit and not much cash, changing out this part is a pretty good gamble to fix this issue compared to the cost of having the pros look at it.

OK, I haven't done a thing to the car, because, (go figure) I haven't had the problem again. The car is running smoothly. I have to go for an inspection this month, so I am going to mention it when I get to the dealer and see what they say. Computer/electrical glitch? If it was something mechanical in nature, I'm assuming it would continue to be a problem. I can't figure it out.

OK, I haven't done a thing to the car, because, (go figure) I haven't had the problem again. The car is running smoothly. I have to go for an inspection this month, so I am going to mention it when I get to the dealer and see what they say. Computer/electrical glitch? If it was something mechanical in nature, I'm assuming it would continue to be a problem. I can't figure it out.

Wondering if the weather has cooled where you are since your symptoms first appeared... my 2002 Saturn L100 transmission was particularly quirky after a good warmup on a hot day... cooler temps and/or shorter drives did not usually make the symptoms appear.