Transmission Mounts & Crossmembers

Factory transmission mounts are typically made from rubber. Performance versions use urethane or polyurethane (unless a solid mount design is used in racing applications), which is more robust, creating less flexing. These materials also absorb vibration that can transfer to the rest of the vehicle body, being felt by the driver or passenger while moving.

The transmission mount bracket also creates a strong and secure connection between the transmission and frame or mounting point. This prevents movement, which can cause damage to both the engine and transmission if they get too far out of alignment with the vehicle. When power is applied from the engine, securing the transmission allows more energy to be diverted to the output shaft, which leads to the wheels.

A transmission mount performs two main functions. The first is to secure the transmission (and engine) in place while it is transferring power to the wheels. The second is to absorb and dampen vibration so that less is felt by the driver and passengers in factory automotive applications.

Depending on the year, make, model, and transmission configuration, there can be anywhere from one to three mounts in most cases. Rear-wheel drive transmissions typically use one mount, while front-wheel drive cars use two or three mounts in many vehicles to secure the transmission.

There are a few common ways to tell if a transmission mount is broken. First is a visual inspection. If the mount looks damaged or has separated, you have a bad transmission mount, which needs to be replaced. If it passes the visual inspection, the next step is to appropriately raise the vehicle onto the jack stands. With a floor jack under the transmission, push it up independently from the rest of the vehicle slowly. If the vehicle moves with the transmission, not showing much give using a floor jack, it is working correctly. If the transmission begins to move and the vehicle doesn't respond, the mount is separating and needs replaced. Another option requires a second person and increased emphasis on safety. With the engine running and the hood open, set the parking brake. Then put one foot on the brake pedal to hold the vehicle in place while the engine is running. Next, put the vehicle in gear, and with the other foot, slightly press on the gas pedal to raise engine rpms (it does not need to be raised very high). The spotter at the side of the vehicle looking into the engine bay (not in front of the vehicle to avoid injury) can watch to see if there is excessive movement of the engine and transmission in relation to the vehicle as torque is applied on the mounts while the brakes hold the car still.

A Transmission mount or bracket can run anywhere from around $20 to over $200 depending on the vehicle's year, make, and model. The transmission mount's replacement cost for labor can vary greatly as there are many different types, numbers, and locations, depending on the vehicle. The hourly labor rate for transmission mount replacement will also vary depending on the repair facility.

The steps for transmission mount replacement in auto or manual gearboxes will vary greatly, depending on the vehicle's year, make, and model. In most cases, the first step is to raise the vehicle safely and properly secure it with jack stands to gain access underneath (for lower transmission mount applications). Next, the transmission is secured as you remove the mount so that it doesn't shift. This can be done by properly using a floor jack for support. Then the transmission mount can be unbolted and removed. In some cases, the transmission will need to be raised to provide room for removal of the mount.