All vehicles have one or more transmission mounts that support the weight of the transmission. Although the mounts are designed to last the life of the vehicle, they can eventually wear out, resulting in some noticeable symptoms.
What is a Transmission Mount?
A typical transmission mount consists of an outer metal frame, which bolts to the transmission and chassis, as well as an inner rubber portion that absorbs vibrations. In some cases, the rubber portion is filled with liquid.
Transmission mounts can wear out due to long-term exposure to the elements or from regular use over time. Also, premature failure can result from fluids leaking down onto the mounts.
A worn-out transmission mount should be replaced right away to prevent further damage to other parts of the vehicle.
The Most Common Signs of a Bad Transmission Mount
Do you think your car might have a bad transmission mount? If you’re noticing one or more of the following symptoms, you might be right.
The most common sign of a worn-out transmission mount is a clunking noise. Usually, the sound is most noticeable during hard acceleration, abrupt braking, or when putting the transmission into gear.
The rubber portion of the transmission mount helps absorb vibrations from the transmission and engine. As such, if the transmission mount fails, vibrations may travel through the chassis and into the cabin of the vehicle.
Excessive Transmission Movement
Worn-out transmission mounts can allow the transmission to move around more than it should. It’s unlikely that you will notice this movement during regular driving. But there’s a good chance you (or your mechanic) will see the movement if a power brake test is performed.
Power braking involves putting the transmission in drive, holding one foot on the brake, and lightly accelerating the engine without moving the car. An assistant should be watching the engine compartment during the test.
A worn-out engine mount or transmission mount will allow the powertrain to move up and down excessively during power braking.
Can a Bad Transmission Mount Cause Slipping?
The answer is almost always, no—a bad transmission mount will not cause the transmission to slip. But there may be some rare cases where a failed mount causes enough movement to throw off the manual shift linkage or the throttle valve linkage (on an older vehicle), thereby impacting shift quality and shift timing.
How Much Does a Transmission Mount Replacement Cost?
If you choose to have a professional replace your car’s transmission mount, you can usually expect to pay somewhere from around $200 to $800 to get the job done. Of course, the exact price will depend on a variety of factors, such as the year, make, and model of your vehicle.
You can save money by replacing the transmission mount yourself if you have the tools and the know-how. CarParts.com has a wide variety of replacement transmission mounts available for various makes and models.