Tranny question

[joeoby78]

I'm in no way shape or form a transmission person so bare with me if this is a common problem. I had my tranny rebuilt about 6-7 months ago and have had it back to the rebuilder quite a few times for different problems. He has honored his warranty and fixed all the previous problems. For the most part I am happy with his work, but there is an ongoing problem that he can't seem to figure out. The warranty is almost up in about 500 miles and i want to try and figure it out on my own so I can tell him to fix it. Here it is. It started out when I would go WOT and then back down to lock-up speed, 45ish mph, the rpms would hop until I got to 50-52 mph, then it would smooth out. Now I have noticed that whenever i drive to work, no WOT at all, after getting off the freeway and cruising down the access road the same thing happens. Lock-up kicks in at 45ish and the rpm starts bumping, like i'm poping the gas pedal, and it bumps up about 300-400 rpms until I get to about 53-55mph and it stops. Any ideas? I'm thinking torque converter, I am doing a heads and cam before too long and going with a stall converter so if that's what it is, i'll hold out. The tranny shifts good and hard and doesn't leak nor have burnt fluid. And if I hit the tow/haul when it is acting up, it stops, but goes right back when I trun the tow/haul off.

'05 CC 5.3L, tuned, LT's, 3" exhaust, 4L65E, 150 shot

[motorholmes]

Yeah it must be the converter locking and unlocking? I bet you could fix it with a tweak on your tune

[joeoby78]

I'm in no way shape or form a transmission person so bare with me if this is a common problem. I had my tranny rebuilt about 6-7 months ago and have had it back to the rebuilder quite a few times for different problems. He has honored his warranty and fixed all the previous problems. For the most part I am happy with his work, but there is an ongoing problem that he can't seem to figure out. The warranty is almost up in about 500 miles and i want to try and figure it out on my own so I can tell him to fix it. Here it is. It started out when I would go WOT and then back down to lock-up speed, 45ish mph, the rpms would hop until I got to 50-52 mph, then it would smooth out. Now I have noticed that whenever i drive to work, no WOT at all, after getting off the freeway and cruising down the access road the same thing happens. Lock-up kicks in at 45ish and the rpm starts bumping, like i'm poping the gas pedal, and it bumps up about 300-400 rpms until I get to about 53-55mph and it stops. Any ideas? I'm thinking torque converter, I am doing a heads and cam before too long and going with a stall converter so if that's what it is, i'll hold out. The tranny shifts good and hard and doesn't leak nor have burnt fluid. And if I hit the tow/haul when it is acting up, it stops, but goes right back when I trun the tow/haul off.

'05 CC 5.3L, tuned, LT's, 3" exhaust, 4L65E, 150 shot

UPDATE:
I went back to the tranny guy and had him check the transmission and just a general inspection. Told him I wanted to get the problem with the surging figured out and fixed. He had it a day, and when I picked it up he told me he couldn't get the truck to surge like I had described....... B.S. i thought. Then he proceeds to tell me when he consulted the A.T.R.A website for advice on the problem, it told him I needed to "reprogram" the PCM. Now, I have a custom street tune through a guy who uses HP tuners, and the tranny guy knew that. The tranny guy tells me that is not the same thing, there is a difference between tuning and reprogramming. Now I'm no expert on vehicle computer tuning but that sounds like a load of sh*t. Anybody else think the same? The tranny guy said he had a guy who would reprogram the PCM for $150, again, I am suspicious so I didn't do it and just took my truck. I think I am through jacking with this tranny guy and ready to explore other options, warranty is up anyways. Does anybody have any thoughts, ideas, or advice?

[foggy]

have your torque converter lockup speed raised up to 53.

[joeoby78]

have your torque converter lockup speed raised up to 53.

Yeah, I wasn't sure if that was possible through the tune or if it was mechanical in the torque converter itself. I am trying to get in contact with my tuner guy, he's a good tuner but hell to get on the phone. LOL!

[96/chevy/pu]

It is possible that GM has updated the calibration to correct this issue, so in a sense he's not lying but if your tuner is on the up and up he would be flashing your computer with GM's latest calibration or could simply tune the problem your having his self.

BB