Transmission problem when pulling out.

[speedracer25f]

I have a 2003 Pontiac Grand Prix Gt with 134,xxx miles on it. I have an intermittent issue that I was hoping someone might know the cause. When I drive the car, sometimes, randomly when pulling out from a light, it will rev up a bit and slam into gear. Almost like you are doing a neutral drop but not that hard. I pull out slow and once in a while you can tell it still happens. Other than that it shifts perfectly fine, it never slips, and drives excellent. Its only happening less than 10% of the time. I did do a filter and fluid change and it still seems to be happening.

[buickman104]

What are your trans fluid temps?

[ADrugDealer]

Sounds the inner surface of the input clutch piston is worn out, this will cause a bang-start. Revving up gets the pump shaft spinning faster, so more fluid moves to the area and then the piston goes and that's the bang shift part.

Three options:
1) New Transmission from TEP (Duhh)
2) Drive it until the thing fails completely, then replace/rebuild it
3) Open it up, pull the input/3rd drum, replace piston, seals, clutches and be on your way.

[EJOUIE]

Mines been doing the exact same thing for 80,000 miles. Fluid temps are fine along with the color. Hasn't gotten any worse either. May just be another quirk in these transmissions.

Also happens randomly regardless of fluid temp. Never a hard bang by any means right? More like a mild jerk like you had your foot on the brake for a second sound about right?

[ADrugDealer]

read above statement.

[RM686]

1999 Grand Prix GT. I am on my 3rd transmission at 170,000 miles. This last one reman shifted badly from day one. I change the Throttle positioner sensor which help tremendously. The only problem I have now is sometimes when I come to a rolling stop at a stop sign and feed gas I get the jerk you are talking about. The trans has a 3 year 100,000 warranty. They can not find anything wrong with it as the jerk is only once in a while and was not happing when I brought the car back. These transmissions s**k. I would run it into the ground as even shelling out $2800.00 for a reman will not guarantee fixing your problem.

[BillBoost37]

If the transmission is built properly, this should never be an issue.

Also.. sometimes there are other issues like your throttle sensor that will effect how the transmission shifts. While it seems like a trans issue.. it might not be the case.

[RM686]

Changed my throttle positioner sensor if you read my post. Improvement but no cigar.

[2004l67]

I've got the same thing going on, did the Transgo kit and it seemed to get better but it's back to normal. I thought the cause of this was the pressure control solenoid?

Food for thought, if I manually put the gear selector in 1st before pulling out it doesn't happen.

[Grimsin]

When you manually select first it ups the line pressure.
you can get a tune to bandaid the issue. But it will come back.

I had this this issue. It will get worse and worse till you are afraid to come to a stop lol. Dont bother with lucas it don't help.
Just replaced my trans due to this issue so your options are either rebuild or replace with jy trans.