94 K1500 (z71) Torque converter lockup issue

[Koto87]

My truck will start to shudder and jerk when hitting overdrive speeds around 45-55mph. At first, it also made a metal coming apart sound. So I parked it and replaced the torque converter thinking this was the problem. After the torque converter install the truck definitely drives better on take off up until I hit the overdrive or lockup speeds. After the new torque converter, the loud metal sound is gone; however, the shudder/jerking is still there. The shudder/jerking is from the drop and rise in rpm that is happening as if it is going in and out of gear or lockup.

I am at a loss for what to check next. Is there a TCC solenoid on this truck? If so where is the location? Are there any other things I should check? Or a way to diagnose this further? Thanks in advance for all input.

The truck is bone stock.

 

[PlayingWithTBI]

Put a scanner on it so you can see if the TCC is being told to lock and unlock. Watch your RPMs on the log too. Sometimes the ICM will start wigging out when warm and the PCM will throw fuel at it thinking it's revving a lot higher than it really is.

 

[Koto87]

Put a scanner on it so you can see if the TCC is being told to lock and unlock. Watch your RPMs on the log too. Sometimes the ICM will start wigging out when warm and the PCM will throw fuel at it thinking it's revving a lot higher than it really is.

Awesome! thank you, sir. I will check out the ICM, I did not even think about that. The ICM could also be why I have been having a lean issue and the RPM electrical flicker at times (like the rpm bounce up but the engine doesn't actually change rpm).

 

[that_Z69]

I know this is a long shot and the Koto87 is no longer active,but did the ICM end up being the issue?