Auto Trans shift problem on 96 Grand AM 3.1L

[scottsman]

Intermediate mechanic, but learning! My Grand Am 3.1L auto trans is not shifting properly. It shifts from 1st to 2nd @ 25mph, then doesn't shift after that. Is there a vacuum line I am missing off the transmission, or possibly a solonoid? I don't know where to look????

[voyager]

sounds like you're stuck in "L" - a gear selector problem. try driving in L.. what happens then? what about "OD"? i assume you're
having this problem in "D"

[Flatrater]

Ok do you have a 3 speed or a 4 speed? Does it have a big round cylinder at the front of the trans below the throttle body?

What does the engine sound like above 30 mph? Does it sound real loud?

It is possible that the trans is sticking in 2nd gear but it is more likely that your transmission is slipping causing your problem. Have you ever replace the trans filter and fluid? What color and what trype of smell does the trans fluid have? Is the tran fluid low?

The more info you give the more help you can get!

[scottsman]

My apologies for not providing more info. I could really use some expert advice. Here is what I have and what has been checked.

1. Car is 4 speed trans and has problem when shifter in D position, although manual shift produced same results once changed to 3rd, then back to D.
2. Trans Fluid & Filter were been changed 7 mo. ago and was a little dirty, but no deposits in pan (done by myself).
3. Above 30mph, car sounds like it is being reving high (at 3000-3500rpm when driving 40-45mph)
4. Car has been hooked to Snap On tester and driven, which indicated that computer is telling car to shift, but car not responding. During test we manually shifted through 1st, 2nd, 3rd & D. During manual shift, car responded to 1st & 2nd, but not to 3rd or Drive.
5. Car shifts from 1st to 2nd, then stays in 2nd without shifting to next gear.
6. I heard no major break in the trans, and the fluid is full and a little brownish/red, but not burnt or gritty to touch.
7. No check engine light either?

This is what I have so far and I could use some advice. I am leaning towards the 2-3 (aka "B") solenoid being bad, causing the rest of it not shift, but am not a transmission man. I purchased the complete shop manual from Helm Inc for this car, and am willing to tackle the job to fix it, but am not sure what else it could be.

[Puckman27]

back in march my check engine light came on while i was going back to school, so i took it to a dealer and they said that a code came up saying the transmission was slipping. I ended up getting a whole new Valve Body, along with the entire day of labor fees (total of $1200). i noticed the difference afterwards; before if i floored it my car would shift out of first @ around 5500 rpm, now it shifts around 4500-5000 and much quicker. I donno if it's the same case w/ your car, but it could be a possibility since its slipping or not even shifting at all. if thats not it, i'm hoping ur problem is a little cheaper, or not requiring a whole new transmission.