Im having a problem with the wifes 2wd yukon 5.3 4l60. It started today shifting from first to 3rd or 4rth i cant tell didnt want to drive it very far. It dosent slip just revs up to about 4k and then shifts strait to 4rth i belive and dosent lock the converter up didnt know if somthing in the vaulve body is stick or one of the shit solenoids.