Automatic Transmission Mount – GM (84056866)

Automatic Transmission Mount is a compliant mounting element that holds a drivetrain component in place while absorbing movement. The bonded rubber fails from heat and oil long before the metal does.

Replace the Mount when the bonded rubber is cracked, when fluid has leaked from a hydraulic mount, or when vibration at idle has increased. Check the other mounts before deciding how many to change.

This Mount is listed as part 84056866 (Transmission Assemblies). Where a number has been superseded, the current reference is the one that ships, so check any supersession note before ordering.

The stock here is genuine GM, and this Mount keeps the original engineering number, which matters once a number has been superseded more than once.