Here will mainly describe the failure and maintenance of the mechanical friction main clutch and the friction clutch of the automobile winch system. Most of the main clutches used in construction machinery are mechanical friction type, and most of the medium and small horsepower machinery are single or double disc clutches. High horsepower construction machinery usually has a large friction index, as well as a multi disc wet test clutch of powder metallurgy materials with high positive pressure discs. Friction clutches are divided into two types according to different pressure conditions. The former is mainly used for small and medium horsepower mobile engineering cranes, and the latter is mainly used for large crawler chassis cranes.

1. When the clutch slips, the vehicle resistance increases and the vehicle speed decreases significantly, while the vehicle speed decreases slightly, that is, the clutch slips.

2. Clutch jitter. When the clutch is gently connected according to the normal operation, the vehicle will not gradually and steadily increase the speed, but will start intermittently, and even make the vehicle shake until the clutch is fully engaged. This scenario is often referred to as clutch jitter. Clutch jitter will cause driver discomfort and accelerate the damage of transmission components due to impact load.

3. Incomplete clutch disengagement incomplete clutch disengagement means that when the clutch lever or pedal is in the disengaged position, the driving plate and the driven plate are not completely disengaged, and there is still some power transmission.

Incomplete clutch separation will make it difficult for the transmission to shift, resulting in tooth collision and damage to the tooth end; At the same time, the surface damage of the pressure plate and friction plate will also accelerate, causing the clutch to heat up.

4. Abnormal sound of clutch abnormal sound of clutch mainly occurs in the process of clutch connection or separation and when the speed changes. Because the sound is mainly due to abnormal friction or impact between parts, it is usually relatively clear. If the clutch is just combined, sometimes there will be "sand", "sand" sound, combination, separation, or the sound of "CLA" and "CLA" when the speed changes suddenly.