Fitment: The T-47781AC Repair tool is designed for the removal and installation of specific transmission. Fits for the 1-2-3-4 and 3-5-reverse clutch drum and for the 6L50E, 6L80E, 6L90E transmissions Features: 1) The large drum in these GM transmissions is difficult to handle without the use of our specialty clamp. If you're tried to pick up the drum with your fingers, which will slip from them. The drum also difficult to put in place without this tool .