Shifts hard and jerks under hard acceleration.

Shifts hard from 1st to 2nd gear. Jerks under hard acceleration. It seems to slip and shake if I accelerate to hard in any gear. Replaced filter and fluid. All mounts seem to be fine. 3.0 V6, 17bolts on transmission pan.

Thottle positioning sensor? if trans has overdrive could be a lock up piece, dont remember name of it. there is a lucas oil product that might help. if it is the overdrive.