Unfortunately, transmission problems are one of the most common issues that require major repairs to be done. However, this does not mean that the clunking sound you hear when shifting to reverse gear must be something so serious you have to empty your bank account to pay for repairs. If you get clunking noises each time you shift to reverse gear, the most likely cause is a bad motor or transaxle mount making a metal-on-metal tapping sound.
While engine and transmission mounts serve the same purpose, namely, preventing excessive vibration, both are distinct from each other. However, engine mounts, also commonly known as motor mounts, are designed to shoulder the bulk of absorbing engine vibration.
Unfortunately, the motor mount can develop problems just like any other component of a car, leaving it unable to adequately absorb the shock and vibration coming from the engine. If the motor mount comes loose or the rubber deteriorates, the driver will begin to feel and hear the movement of the motor, unlike when the mounts were in excellent condition.
You see, the motor mount comes with a flexible CV joint that makes it possible for the wheels to perform a range of movements. So, you could hear clunking sounds when you shift gears due to a worn-out CV joint. The same is true for the transmission mount. Internal transmission issues can also result in strange noises when you shift gears, but that’s unlikely to be the case if you hear the noise only when you shift to reverse gear.
There are simple steps to find out if a defective motor mount is causing the clunking noise.
- Get the vehicle to a level ground
- Turn off the engine and shift the gear to “Neutral”
- Push the vehicle backward and listen for the tapping sounds
There is also another way to figure out if the clunking sound is due to a bad mount, but you’ll need an extra pair of legs.
Get someone to fully depress the vehicle’s brake pedal. With the emergency brake engaged, let the person slowly accelerate while you stand beside the engine bay to see if the engine is lifting excessively. Repeat the same process but in reverse gear but allowing some hesitation when shifting from drive to reverse.
Besides the motor and transaxle mounts, other things can be responsible for the clunking feedback you get when shifting to reverse gear. It includes problems with the vehicle’s exhaust or steering/suspension/crossmember components.
The crossmember is an important structural component of your car located underneath your vehicle. Its job is to enhance the vehicle’s stability by supporting the vehicle’s engine and transmission while also keeping the body panels aligned.
It’s best to take your car to your local mechanic if you suspect the clunking sound is due to issues in the crossmember components. At the mechanic workshop, they will safely elevate the car and shift the gears to locate the source of the noise. A vehicle has so many moving parts, with one of them being the likely culprit, so it’s best to let a qualified automobile technician diagnose where the clunking noise is actually coming from.