So my transmission went out. Took it to a highly recommened rebuilder. He upgraded parts during rebuild. Upon completion of rebuild, during test drive he says it shifts too early. Burned up one rebuild, and he re-rebuilt the tranny. Still shifting too soon. has 5.13 rears gears, 38" tires. computer has been recalibrated for these adjustmensts. Why would it be shifting too soon? He has had my truck for two weeks and cant seem to figure it out. Do the high dollar mechanic shop scanners show what the tcm thinks the current rear-end ratio is? Maybe the gear calibration didn't take? At a loss. I want my truck back and am trying to help this guy figure out how to make it shift normal under regular throttle conditions. WOT shifts are fine.