Pedal failure
1. Fault phenomenon: when the engine is idling, although the clutch pedal has been stepped to the end, it is difficult to hold the gear, and the transmission gear has an impact sound. After barely putting on gear, the clutch pedal has not yet been relaxed, and the car has moved or stalled.
2. Inspection: Remove the clutch bottom cover, put the transmission into neutral gear, and press the clutch to the end. Then, use the driver to toggle the follower disk. If it can be easily dialed, it means that the clutch is well disengaged, and if it cannot be dialed, it means that the clutch is not fully disengaged.
3. Exclusions:
1. Check whether the free stroke of the clutch pedal is too large and adjust it.
2. Check whether the height of the separation lever is consistent and whether it is too low. Toggle the release fork under the car, so that the front end of the release bearing gently leans on the inner end face of the release lever, turn the clutch for a week to check, if the inner end of the release lever can not be in contact with the release bearing at the same time, it means that the height of the release lever is inconsistent, and it should be adjusted. If the separation lever height is the same, but the separation is still incomplete, the lever height should be checked. Adjust each separation lever to the same height, if it can be completely separated, it means that the original adjustment is not appropriate or too worn. After the disengagement lever adjustment, the free travel of the clutch pedal must be readjusted.
3. If the separation is still incomplete after the above adjustment is normal, the clutch should be removed, and the clutch should be checked to check whether the driven disc is reversed, whether the axial movement is difficult, whether the main and slave disc is warped, whether the separation lever screw is loose, and whether the floating pin falls off.
4. For the clutch of the newly riveted friction plate, check whether the driven disc and the friction plate are too thick. If it is too thick, a spacer can be added between the clutch cover and the flywheel.
5. For the clutch of hydraulic transmission, in addition to the above inspection, it should also be checked whether the brake fluid is missing, whether the pipeline is leaking and the air in the hydraulic system should be discharged.
Slip handling
When a clutch slippage occurs, a correct analysis of the cause of the failure should be performed.
1. The cause of clutch slippage
(1) The driven disc friction plate is worn excessively or the rivet is exposed;
(2) The clutch pressure plate spring is too soft or broken;
(3) The free stroke of the clutch pedal is too small;
(4) There is oil stain on the friction plate of the driven disc or it is hardened by aging;
(5) The clutch and flywheel engagement bolts are loose;
(6) The return hole of the clutch master cylinder is blocked.
2. Troubleshooting sequence and orientation
(1) Check the free stroke of the pedal, if it does not meet the standard value, it should be adjusted;
(2) If the free stroke is normal, the clutch bottom cover should be removed, and the clutch cover and flywheel joint bolts should be checked to see if they are loose, and if they are loose, they should be tightened;
(3) Check whether there is oil stain on the edge of the clutch friction plate, if there is oil stain, it should be removed and cleaned and dried with gasoline or alkaline water, and then find out the source of oil stain and eliminate it;
(4) If it is found that the friction plate is seriously worn, the rivet is exposed, aged and hardened, burned and soaked in oil, etc., it should be replaced with a new one, and the new friction plate should not be cracked or damaged, and the depth of the rivet should meet the regulations;
(5) Check the oil return hole of the clutch master cylinder, if the oil return hole is blocked, it should be dredged;
(6) If the fault cannot be eliminated after the above inspection, adjustment and repair, disassemble the clutch and check the elasticity of the pressure plate spring. When the pressure plate spring is good, the length should be consistent, if it is uneven, it should be replaced with a new product, if the elasticity is slightly reduced, the length difference is not large, you can add or subtract the gasket under the spring to adjust.
Exception issues
1. Pay attention to whether the clutch slips, there are several reasons for this phenomenon, the main reason is that the free stroke of the clutch pedal is too small, and the release bearing is often pressed on the diaphragm spring, so that the pressure plate is always in a semi-separated state. Or the clutch pressure plate spring is too soft or broken, the screw connecting the clutch and the flywheel is loose, etc.
2. When the engine is idling, the clutch can be cut off when the clutch pedal is almost bottomed out. Pressing the clutch pedal, feeling the difficulty of gearing or a screeching sound of the transmission gears, or not lifting the clutch pedal after the gear is engaged, and the vehicle starts moving, are all signs that the car's clutch is not fully disengaged.
3. When the clutch pedal is stepped on to 3/4, the clutch should be firmly engaged, otherwise check whether its stroke is appropriate, you can use a ruler to measure at the pedal, first measure the height of the highest position of the pedal, and then measure the height when you step on the pedal to feel resistance, the difference between the two values is the value of the clutch stroke of the car.
4. If there is abnormal noise during the use of the clutch, it is also abnormal. The cause of failure is serious wear of the separation bearing, the bearing return spring is too soft or broken, and the diaphragm spring bracket is faulty.
The separation is not complete
There are two phenomena of incomplete clutch disengagement:
(1) When the car starts, press the clutch pedal down to exceed the free stroke, but still feel that it is difficult to engage the gear; if the gear is forcibly engaged, but the clutch pedal is not fully lifted, the car will move forward or backward, and cause the engine to stall.
(2) It is difficult to shift gears during driving, or the gear cannot be hung up, and the sound of gear impact occurs in the transmission.
The main reasons for incomplete clutch disengagement are:
(1) The free stroke of the clutch pedal is too large;
(2) The inner end of the separation lever is not on the same plane, and the individual separation lever is seriously deformed, broken and worn;
(3) The clutch disc is warped, the rivet is loose, or the friction plate of the new clutch is too thick;
(4) The front and back sides of the clutch driven disc are reversed;
(5) The gap between the keyway of the driven disc hub and the spline tooth of the first shaft of the transmission is too small or stuck, resulting in difficulty in moving.
The diagnosis of such a fault is to drive the car to a flat road, put the gear lever in neutral position, press the clutch pedal, if there is only the driver, you can use a wooden stick to press the clutch pedal down, and resist (pull up the brake lever to make the hand brake work). In the hole under the flywheel housing, use a screwdriver to push the clutch plate, if it can be gently pushed, it means that the clutch can still be cut off, if it can't be pushed, it means that the clutch is inseparable.
The main reason why the clutch disengages poorly is that the free travel of the clutch pedal is too large. Then after replacing the clutch driven disc, due to ignoring the cleaning of the first shaft of the transmission, there are impurities, resulting in too small the gap between the driven disc hub and the first shaft, large moving resistance, and poor clutch separation. When the user buys the clutch disc assembly, he should check whether there is warpage, its thickness should meet the standard, and if it is warped or too thick, it should be replaced.