Torque Convert not locking properly
My truck has 115k on it, and a few weeks ago i started having problems with the torque converter shuddering. It was the second time that I have had this problem with the transmission. The first time I had the transmission serviced and it fixed the shudder problem, about 30k later it came back. I replaced the torque convert, filter and refilled it with Mercon V transmission fluid. It shuddered the first time it went into OD. This transmission has been serviced twice and there were NO metal shaving in the bottom of the pan either time.
I took the truck to a mechanic and he said that the valve body could be wore out or leaking internally, which was based on the fact that the transmission service and replacing the torque converter did not fix the problem.
I hesitated to spend the money on chancing a valve body that may not fix the problem at first. The very next week after talking to him, the truck got to where it did not want to shift in to OD. You would let off the throttle and the engine would idle even going 50. So I had the valve body replaced.
The Valve body fixed the shifting into OD problem, but not the TC problem. When the truck goes into OD, it feels like the TC is partially lock, I can try to accelerate and I can see the tack jump up some like the TC is locked but not completely. To get the TC to completely lock, I have to back off of the throttle some. If im not paying attention when it goes into OD, the TC will vibrate bad (doesnt feel like a shudder at all) like its trying to lock, I back of the throttle some and I can see the RPM drop down to where it should be.
I know it sounds weird, but that is what the truck is doing I wish I could explain the problem better.