GMC Troubleshooting Questions? Ask a Mechanic for Answers
I wonder if this has a lock-up torque convertor and that is giving you a problem.
Is this an automatic transmission?
Ok, is this the C1500 2WD or K1500 4WD?
yeah, I see in 3rd-D4 the torque convertor clutch is applied.
I am reading that the torque convertor should be locked up in 3rd or 4th gear when the speed is above 24 mph and several other things, but first to determine if it is even the torque convertor lockup that is even causing the problem. I suppose the easiest way to check is to just disconnect the TCC for now. Test drive it and see if it still shudders.
Let me see if I can find a fuse to pull or something, give me a minute or two.
Yes, the gage fuse, remove it and see if it still shudders, if not, then we can start diagnosing that tcc circuit, cause I just read the "4th gear signal to ECM. This signal will not prevent TCC engagement, but could cause a change in engage/disengage speed points."
You should be able to. If you are on a windows pc, wait I'll just send you a *.doc which opens with Microsoft word,
Have you had a chance to check that yet?