Clutch brakes are used in a wide array of different vehicle types. You’ll find this brake type in cars, trucks and heavy duty trucks.

The clutch brake has a circular disc with a friction surface that connects to the input shaft of the transmission between the release bearing and transmission. The purpose of the clutch brake is to stop or slow the input shaft from turning.

It helps prevent premature wear of the internal transmission parts during those initial shifts. To understand this in more detail, let’s consider what is going on when a heavy truck transmission is shifted from neutral to first or reverse. When a truck is in neutral and the clutch pedal is not depressed, the master clutch is engaged.

This causes power from the engine to drive the transmission input shaft, resulting in the rotation of the shafts and gears in the transmission. When this occurs, the gears won’t be engaged in a way that produces power to the drive shaft. Now, parts of the transmission are spinning but just idling.