I know I am in the wrong forum, But after all, It IS a Chevy with another 4L60E problem.. I think?!?!
Truck:
2000 Tahoe Limited, 5.7L, 4l60E

Problem:
When I start my truck it will go into gear and run perfectly. After running for about 10 minutes I can start to hear a noise comeing from the torque converter.. Sounds like a metal bowl with pennies in it, swirling around?.?.. Anyways, Once this sound starts the transmission starts to slip real bad under accelleration ( almost like it has a 3000 stall converter ). It also will start to jump between 1st gear and 2nd. If I continue to drive it, it will eventually stop moving, like its in neutral.. At that point it will not go into any gear no matter where the shifter is placed.. And it still has that racket comeing from the converter.. The other thing is that when the transmission starts acting up, the motor starts running really funny.. The best way I can explain this is like so.. When you hit the speed limiter in your vehicle and the computer detunes the engine to slow you down.. thats Exactly what it starts doing.. Almost like the computer senses there is a problem with the trans and detunes the motor..
Now back to the transmission. When It gets to the point that it will not move no matter what gear I am in; if i shut the truck off for 30 seconds, turn it back on, it will drive and shift 100% perfect for about 10 mins with no more noise from the converter, then it starts all over again..
So.. As you guys can see I have a real issue on my hands here.. I cannot determine if it is the transmission/torque converter just for the fact that my truck starts running funny when this all happens, Kinda makes me think it might be a computer problem??..Not Sure... Can the computer be sensing a problem with the trans and detuning the engine? And why does the problem completley go away for another 10 minutes once I restart the truck..
Any help would be GREATLY appreciated!!..
Ps.. I do have a Matco Determinator Scan tool.. I do not pull any codes when this is happening.. But I am able to view a live graph of all the trans pressures.. Unfortunatly I dont know what to look for with this tool..
Again .. Help Please!!
Thanks
Chris

 

If you stop moving you have a trans internal issue there is no electronics issue that will cause loss of all movment, With the noise I would suspect the converter has failed and contaminate from it are clogging the filter.
The detuning is possible withthe noise as the PCM may think its spark knock or something of that nature.
I would pull the pan on the trans and see whats in there.