2000 Chevrolet Blazer - Transmission Main Shaft Bearing

What is a Main Shaft Bearing?

The main shaft, also referred to as the main drive, in a manual transmission is a combination and connection point of both the input and output shafts. The input shaft receives power from the engine and transfers it to the output shaft using the main shaft. After receiving the power, the output shaft then transfers that power to the vehicle's drive shaft or CV shaft, which powers the differential or axle shafts to move the vehicle. The main shaft bearing allows the main shaft to rotate freely with minimal friction while also keeping it in place and aligned. The bearing must remain lubricated, so if you notice leaks, noises like grinding or clunking while shifting, or poor transmission shifting and power transfer, check your fluid levels, output and input shafts, and your main shaft bearing for damage. This will typically require a complete transmission teardown, so ensure a complete diagnosis before beginning your repair to ensure the main shaft bearings require replacement. If you need bearings, or a main, output, or input shaft for your transmission repair, check out O'Reilly Auto Parts to find all the manual transmission parts you need to keep your vehicle driving its best.