Why does my gearbox grind?

A grinding noise when shifting gears is often caused by worn or damaged synchronizers. Synchronizers are components in the gearbox that help match the speed of the input shaft (driven by the engine) and the output shaft (which drives the wheels) when shifting gears. When synchronizers are worn or damaged, they may not be able to align the speeds of the two shafts properly, resulting in a grinding noise. Grinding noises can also be caused by low transmission fluid levels or damaged gear teeth.

Low transmission fluid levels: Your transmission needs the proper amount of fluid to work properly. If the fluid level is too low, the gears and other components in the transmission will not be properly lubricated. This can cause them to grind or malfunction.

Damaged gear teeth: The gears in your transmission are responsible for transferring power from the engine to the wheels. If the teeth on these gears are damaged, they can cause a grinding noise when you shift gears. Gear teeth can become damaged due to high speeds, excessive torque, or inadequate lubrication.

Other gearbox faults that can cause grinding include:

- Damaged bearings or bushings

- Bent or misaligned shift forks

- Faulty clutch hydraulics

- Loose or damaged engine mounts