Performance Transmission Mounts

The best performance transmission mount depends on your car and how much firmness you want: a Perrin Transmission Mount for a 2002-2025 WRX, 2004-2021 STI, and other listed Subaru models, a Kartboy or Torque Solution mount insert for a BRZ or FR-S, or a Torque Solution billet aluminum mount for a 370Z or G37. Full mounts replace the factory piece, while inserts fill and stiffen an existing mount. Check your year and model before ordering.

The transmission mount supports the gearbox and controls how much it moves under load. A worn or soft mount can let the drivetrain shift under load, which you may feel through the shifter. A firmer mount or insert reduces that movement and can make shifts feel more direct, at the cost of transmitting more vibration into the cabin.

Decide first between a full replacement mount and an insert. Inserts are usually the smaller, simpler step and keep the factory mount body. Full mounts, including billet designs, are the firmer commitment. Compare related parts in our Engine Mounts and Drivetrain collections, as mounts work as a system.

Perrin covers the broadest Subaru range here with the Perrin Transmission Mount, listed for the 2002-2025 WRX, 2004-2021 STI, 2005-2009 Legacy GT, and 2004-2008 Forester XT, plus a separate Transmission Mount Support for the FR-S, BRZ, 86, and newer BRZ and GR86. Perrin is known for Subaru-specific drivetrain and chassis parts, shaped for each platform rather than one universal mount.

Cusco is represented by a Reinforced Differential Carrier listed for the 2015-2026 WRX, 2008-2021 STI, and 2010-2014 Legacy. Cusco is known for reinforcement parts that reduce drivetrain and chassis movement, and a reinforced carrier limits driveline shift under load just as a mount does.

Torque Solution offers both ends of the range: a Billet Aluminum Transmission Mount for the Nissan 370Z and Infiniti G37, non-AWD only, in the Torque Solution Billet Aluminum Transmission Mount, and a Race mount insert for the 2013 and newer BRZ and FR-S. Torque Solution is known for mounts, inserts, and bushings that let owners choose how firm they want the drivetrain to feel.

Kartboy takes the insert route for the FR-S and BRZ with its Transmission Mount Insert, listed for the 2013-2016 FR-S and 2013-2019 BRZ. Kartboy is known for focused Subaru shifter and drivetrain parts, and an insert fits that philosophy: a targeted change to shift feel without replacing the whole mount. For more on how parts like these change the driving feel, read How Can Aftermarket Parts Improve My Vehicle's Handling?

Will a firmer transmission mount increase vibration?

It can. Firmer mounts and inserts transmit more drivetrain vibration into the cabin. That trade-off is normal and is the main reason to choose the firmness level carefully.

What is the difference between a mount and an insert?

A mount replaces the factory unit. An insert fits into or alongside the existing mount to reduce its movement, keeping more of the factory hardware in place.

Do I need a tune after fitting a transmission mount?

No. A transmission mount is a mechanical support part and does not change engine calibration.

Should I replace engine and transmission mounts together?

Inspect both, because they share the job of controlling drivetrain movement. Replacing one very worn mount can expose movement in another worn mount.