Automatic Transmission Mount Bushing

What Is an Automatic Transmission Mount Bushing?

A transmission mount holds the rear of the transmission — or tailshaft — securely to a crossmember, which is a support welded or bolted to the chassis. At the heart of that mount is the bushing: a cylindrical-shaped rubber sleeve that acts as a buffer between two metal components, supporting and isolating the transmission system from the vehicle's chassis to reduce vibrations, noise, and help transfer power efficiently.

These components play a pivotal role in ensuring seamless gear shifts, reducing friction, absorbing vibrations, and maintaining overall stability in a vehicle's transmission system. They function as a barrier between metal components, preventing direct metal-to-metal contact — which not only slashes friction but also elongates the lifespan of the transmission system.

Why Transmission Mount Bushings Matter

Over time, the bushing material degrades from heat cycles, engine torque, and general wear. When transmission mount bushings go bad, they cause vibration and clunking that can be felt throughout the cabin and drivetrain. Worn or broken transmission mounts can lead to misalignment of the driveshaft, which can cause CV or universal joints to fail.

You can determine if the transmission mount is at fault by wiggling underneath the car and moving the transmission tailshaft back and forth and up and down — anything more than an inch of movement indicates a bad transmission mount. Catching this early saves significantly on downstream drivetrain repairs.

Rubber vs. Polyurethane: Choosing the Right Bushing Material

Transmission mount bushings are crafted from materials such as rubber, polyurethane, or metal. The rubber or urethane bushing isolates drivetrain vibration and reduces noise levels in the vehicle's cabin. Stock rubber bushings prioritize comfort and noise isolation, while stiffer polyurethane or synthetic elastomer options are favored by performance enthusiasts who want more precise drivetrain feedback and reduced mount flex under hard acceleration.

For daily drivers, a direct-replacement rubber bushing restores factory isolation and eliminates unwanted noise. For tuned or track-oriented builds, a firmer insert bushing can dramatically improve shift feel and driveline response without requiring a full mount replacement.

Featured Brand: Whiteline Suspension

Whiteline Suspension is a globally respected name in performance suspension components. Whiteline boasts a worldwide reputation as a manufacturer of replacement, enhancement, and performance suspension components that deliver significant gains in vehicle balance, steering precision, grip levels, and outright driving performance. Their transmission mount bushings reflect the same engineering philosophy applied to their broader suspension lineup.

Whiteline's approach to transmission mount bushings centers on reducing unwanted compliance in the factory mount. Their low compliance polymer insert reduces the lag in response and feel by removing the slop from the rubber transmission mounting, achieving a crisp feel for on/off throttle applications. After extensive development and testing of materials, Whiteline created a progressive, long-chain synthetic elastomer that delivers the combined physical advantages of solid bushings with the extreme flexibility characteristics of rubber.