Quick Shift ,Shutter and Stall

[Lugnut]

My car ran fine and then it began to shift from first to second and bog down. At normal driving you start off it stays in first for about 2 seconds and then shift into second and bogs down bad, then you give it some gas and it up shifts and is fine. Also when you come to a stop it shudders like if you had the clutch out on a manual shift and then sometime it even stalls. I had the transmission taken apart and the insides were fine. The guy who took it apart said it must be the torque converter, I changed it but still have the problem

 

[WarpSpeed]

I'm not an expert, but it sounds like the torque convertor is locking-up early, or not unlocking at coast down. You might try unplugging the wiring harness at the transmission to see if anything changes.
It could be a bad torque convertor solenoid(inside the trans), or a wire grounding out maybe. You know, it takes a negative signal to lock the convertor. Plus, the convertor won't lock-up in first,,,,,,, except by an act of god.

 

[CaPPY]

Check my post "Weird lockup/unlock" below on Dec. 17. It sounds almost identical to my problem. It was the solenoid. I got a GM one from a dealer...didn't have the guts to try an aftermarket one. Shifts fine now.

 

[Lugnut]

I unplugged the connection on the transmission and it stalled again when I stopped. Can the solenoid be stuck closed and keep the converter locked??

 

[WarpSpeed]

Oh yes... If you pull it down in to 1st manually when slowing to a stop, does it still stall? If not, I'd say it's got to be the solenoid.

 

[Lugnut]

Thanks for the help,no more stalling and shifts are back to normal. I changed the TCC solenoid as suggested and the trans is not stalling anymore and the quick shift to 2nd is gone. Actually it was harder to get the part than install it. The parts store gave me the wrong one on the 24th and had to wait until today to get the right part.

Thanks again for the help,
Glenn