Transmission Prob-Any Ideas Where to Start?

[dpmikeyted]

'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!

[GTP Dad]

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.

[dpmikeyted]

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.

[Allbert]

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.

[maxwedge]

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.

[Allbert]

Originally Posted by maxwedge

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/vbul...&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.

[dpmikeyted]

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.

[Allbert]

Originally Posted by dpmikeyted

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.