Bearing, gear and shaft wear are the most common causes of noise. As gear tooth faces and bearing races wear, they develop groves and small pits. While these are only small at first, they will gradually become larger, and as they grow, these imperfections will cause even more noise to occur.

How do I stop my gearbox from making noise?

What noise does a bad gearbox make?

Often, bad automatic transmissions will emit humming, buzzing, or whining sounds; manual transmissions emit harsher mechanical noises, such as clunking. Some of these noises may relate to the engine, exhaust system, drive shaft, differentials or even a wheel bearing.