Just had my trans rebuilt and the torque converter is screwy

[wexy21]

Ok guys, need some suggestions here. I just had a complete rebuild on my stock trans and when I am driving at maybe 40mph and up the torque converter will turn on and off at weird times. If I slowly accelerate it will lock, but as soon as I let off the gas you can hear it unlock. I may have that backwards, but it basically feels like it is shifting up and down constantly. I need to know what to show my trans shop so that they can address this correctly. They claim to know about these trucks and are a reputable shop who work on two police stations cars, but i'm afraid they might not have built it right. I already had an issue with it two weeks after picking it up. Third gear went completely out and when they took it back a part they said it was a defective drum so replaced it. So now I am too nervous to even drive it, it feels like i'm just waiting for that to happen again. I just want to know what the issue can be with the torque converter and how to let this shop know about fixing that correctly.

 

[Don W.]

Re: Just had my trans rebuilt and the torque converter is screwy

Have you, or did they, set the TV cable correctly?

 

[wexy21]

Re: Just had my trans rebuilt and the torque converter is screwy

I would assume they did. When my transmission went out, I told them that it was possible that I didn't have the TV cable set right which caused it to break. Third gear was completely out when I first brought it to them. That happened about 20 miles after adjusting the TV cable. I thought my trans wasn't shifting right, it was going into 2nd too soon. So I did the adjustment, and then it broke. Could be bad coincidence, or could have just been on its way out already. But I'm sure they would have set it right. The truck shifts pretty hard and at the right points

 

[mattw]

Re: Just had my trans rebuilt and the torque converter is screwy

IIRC the TC is supposed to unlock whenever you let off the gas.. Get a data-logger going and make sure that your TC is acting as commanded by the ECM. If you are running a higher than stock stall the locking and unlocking action will be more noticeable..

 

[wexy21]

Re: Just had my trans rebuilt and the torque converter is screwy

I have a data logger and still learning about code 59. Once I understand that better I'll post up a log. In the mean time, I want my shop to check this out before anything. I just wanted to know what could be causing this. I'm pretty sure that it shouldn't be turning on and off as much as it does. It just seems too much, like it can't make up its mind.

 

[Don W.]

Re: Just had my trans rebuilt and the torque converter is screwy

The long but very informative version:


http://www.tvmadeez.com/article/index.php





TV Cable Adjustment
Procedure:

1. With the engine off, depress and hold down the metal re-adjust tab at the engine end of the
TV cable.


This tab looks like the letter "D" on its side, push hard.


2. Move the slider until it stops against the fitting. (To your right facing it.)
3. Release the re-adjustment tab.
4. Rotate the throttle lever to its full travel position (WOT).
5. The slider must ratchet toward the level when the lever is rotated to its full travel position.
6. The cable may appear to function properly with the engine stopped and cold.
7. Re-check cable after the engine is hot.
8. Road test the vehicle.

 

[mattw]

Re: Just had my trans rebuilt and the torque converter is screwy

TV cable adjustment has nothing to do with TC lockup.. TC lockup is commanded by the ECM which energizes a solenoid in the transmission valve body which routes fluid into the TC which engages the clutch pack...

You need to see if all of this lock/unlock action is being commanded by the ECM or if its happening otherwise(faulty solenoid, wiring, or some other problem). To do this you need to datalog while driving, pay attention to when the TC is being commanded to lock and see if it behaves as the ECM commands it.. If it does then you have a tune/ECM/sensor issue. If its locking/unlocking while the ECM is commanding that it be locked then you have a solenoid/wiring/trans issue..

 

[wexy21]

Re: Just had my trans rebuilt and the torque converter is screwy

Thanks for that info Matt. I think that should help me figure out what to bring to the shop when I take it back. Now that I know how to data log it should be relatively easy to figure out.