Transmission began to shutter at lower RPM's became more noticeable as time went on. Even cruising on highway, you could feel vibrations and shifting between 1st and second and could hear clunks and thuds and then shudders - the whole truck. After 3 different attempts I finally found the torque convertor or whatever they call it in the transmission shot to heck, leaving slivers of metal all over the fluid and other parts once pan removed. I am totally disgusted with GM.

I bought this truck new, and followed maintenance meticulously yet a 75,000 miles transmission fails. What is infuriating is they knew multiple and numerous reports of transmission problems occurred in these truck for many model years even before my purchase. No one told me about the problem they didn't recall the trucks, yet I find out now bulletins were sent out to mechanics as to what to do if customers came in with the problem.

How can I ever trust GM products, dealers, and mechanics every again. And my service people cannot even find the parts for the repair through GM right now. Have to go to other sources. My truck in tied up so far one week. $3500 dollar repair - this is devastating to families who need transportation or cannot afford a huge outlay like this during these inflationary times.

With the vehicle at full operating temperature (195F coolant temperature), when decelerating to a stop light from highway speed, torque converter locked, the transmission seems to be commanded by vehicle electronics to downshift according to shift tables in its firmware so that the engine RPM never drops below "idle" as the vehicle decelerates, so no lugging or surging is apparent to the vehicle occupants. This element of its theory of operation eventually must surrender to the physics of a vehicle speed of 0 mph requiring not just the selection of 1st gear, but also the unlocking of the torque converter to avoid stalling the engine as the vehicle comes to a stop.

You would think that a shift table could easily be amended with an additional field, to unlock the torque converter at speeds s little higher than "idle" to provide a smooth driving experience--a preemptive unlocking of the torque converter at say 1200 RPM as the vehicle decelerates and the transmission selects the appropriate gear for a given road speed.

But sadly, the only command to unlock the torque converter comes only after reaching idle rpm in 1st gear and while still decelerating. I have named this feature "reluctant disengagement."

The result is a 3-2 and 2-1 shift that are somewhere between smooth and rough and that are obvious to vehicle occupants, some of whom comment on the poor downshift behavior. The engine torque loads during these downshifts are not high enough to damage the transmission because the engine is at 0 throttle and the transmission is separately commanded to engage the clutches delicately due to the light torque load.

It's a shame that GM engineers couldn't add a new field to the shift tables to unlock the torque converter before dropping to 2nd and 1st gears with engine at idle.