ok, on upshifts, it slams into the next gear, 2nd to 3rd is probably the worst of all. if you are under hard throttle, the shift is a bit smoother. if your taking it easy, it slams into gear. you can feel and hear the shift, its a pretty good clunk. it only happens when city driving and temperature breaks past half way. from what i was told, it could be torque converter lock up.
it was driven by a gm tech, he said he didnt feel anything, i told him to drive city and let the fan kick in, he said yeah nothing happened. he had no idea what was wrong. if you cant feel the shift it makes at that certain point, you have no feeling at all! when cold, or temp is down, it shifts like it should so smooth you couldnt tell.
now i just found something on the net for the 4t60e (that is the trans right?) about something up with torque converter lock up being some kind of issue. ok but after reading more, im kind of leaning to maybe something up in valve body. just my
once again