How to Diagnose a Bad Transmission Mount

A bad transmission mount can be dangerous because the transmission of your car can slip or even fall. The transmission mount is designed to hold the transmission in place, to keep it from jostling or moving around when you accelerate. If the transmission mount is bad, you’ll hear a banging noise as the transmission bangs against the mount, and the bad mount will place stress on other components. Knowing how to correctly diagnose a bad transmission mount can save you from dealing with more serious car problems down the road.

Things You'll Need

  • Leather work gloves (optional)
  • Flashlight (optional)
  • Check for cracks on the mount. A cracked transmission mount can end up breaking all the way and causing the transmission to fall.

  • Inspect the transmission mount for loose brackets. If the brackets are loose, the mount will lose its grip on the transmission.

  • Look for loose or missing bolts. You don’t have a good mount on your transmission if it isn’t being held tight.

  • Examine the transmission mount for collapsed or rotted rubber, which would indicate a bad mount.

  • Check the transmission mount to see if it is broken or separated. If so, it is a bad transmission mount.