Underdrive Piston – Mopar (4799650)

Underdrive Piston is a reciprocating component that seals the combustion chamber. Clearance and surface finish decide whether it seals correctly, so the bore has to be measured before a replacement is chosen.

Replace the Underdrive Piston when a leak-down test shows air escaping past the rings, when the skirt is scuffed, or when ring lands are cracked. Check the ring end gap in the bore it will run in.

This Underdrive Piston is listed as part 4799650 (Pistons, Rings & Cylinders). Where a number has been superseded, the current reference is the one that ships, so check any supersession note before ordering.

This is genuine MOPAR stock, supplied for the Underdrive Piston with the manufacturer number intact so the reference on the box matches the catalogue.