Ausrücklager

Ausrücklager, English release bearing or throw-out bearing, is a component of manual transmission clutch systems. It transmits the movement of the clutch release mechanism to the diaphragm spring of the pressure plate so the clutch can be disengaged when the pedal is pressed. It is typically mounted at the end of the clutch fork or inside a concentric slave cylinder in hydraulic setups.

In a standard mechanical system, the release bearing sits between the clutch fork and the pressure plate. When the pedal is pressed, the release fork pushes the bearing against the diaphragm spring, reducing the clamping force on the clutch disc and allowing gear changes without torque transfer. In hydraulic systems, a concentric slave cylinder actuates the release bearing via hydraulic pressure; the bearing then presses against the diaphragm spring as pressure increases.

Types and design variations include mechanical release bearings, usually a ball- or roller-bearing assembly, and hydraulic or concentric release systems where the bearing operates within a hydraulic actuator. The bearing is designed to rotate freely against the diaphragm spring surfaces to minimize wear. Materials commonly used include steel with low-friction coatings; some designs use specialized bearings for high-load or high-temperature conditions.

Failure modes and maintenance: typical faults are wear of the bearing surface, contamination, or insufficient lubrication in non-sealed designs, leading to noise such as squealing, chirping, or grinding during clutch operation. Other symptoms include a soft or spongy pedal, difficulty disengaging, or clutch slippage. Replacement is commonly performed together with a clutch kit, since wear on the release bearing often accompanies wear of the pressure plate and clutch disc. Proper installation and alignment are essential to prevent premature wear and noise.