The causes and diagnosis of various abnormal sounds of the drive shaft are as follows:

First, observe the fault phenomenon

1. When the car starts or travels, the drive shaft has a collision sound, especially when it is driving at a low speed on the high speed gear.

2. When the car starts, the drive shaft makes no noise, but when the car runs, the drive shaft has a sound of impact.

3. When the car starts, the transmission shaft has no abnormal sound, and when the car coasting, the transmission shaft has abnormal sound.

The car kept making noise throughout the whole journey.

Second, analyze the cause of failure

1. The flange connection of the drive shaft (or the connecting bolt) is loose, causing abnormal sound.

2, all the grease fitting (commonly known as grease nipple), spider note not into the oil duct jam for grease, fail to filling grease, cross shaft oil seal damage and causes such as oil, caused the spider needle roller bearing under the condition of lack of lubricating oil for a long time to work, make a cross shaft neck, needle and sleeve wear is too large, forming loose kuang is caused by the different ring.

3. The assembly of universal cross shaft is too tight.

4. The sleeve and the fork hole of the universal joint are loose, and the supporting bolt is loose, resulting in the rotation of the sleeve, which makes the fork hole of the universal joint wear too large, and the loose result in abnormal sound.

5, transmission second shaft spline and flange spline wear is too large, the formation of loose and cause abnormal sound.

6. The fixing bolt of the middle supporting bracket of the drive shaft is loose, the middle supporting and the middle driving shaft journal are loose, the back spline of the middle driving shaft and the flange keyway are loose and the back nut is loose.

7. The intermediate supporting bearing of the drive shaft is broken, the bearing raceway is damaged, the bearing is poorly lubricated, and the wear is excessive and loose.

8. The installation position of the middle supporting bracket of the drive shaft is skewed, the bearing pretightening degree is adjusted improperly, the rubber gasket ring sleeve is damaged, the fixing bolt of the middle supporting bracket is screwed too large or too small, which causes the deviation of the bracket position and other reasons, and causes abnormal sound.

9. The universal joint forks at both ends of the transmission shaft are not in the same plane, so that the constant velocity arrangement is destroyed and the abnormal sound is caused.

3. Diagnosis and troubleshooting

1, the car suddenly changes the speed, the drive shaft appears a metal knock, can explain the individual flange or universal joint cross shaft bearing wear is too large and loose, causing the drive shaft abnormal sound.

2. When the car starts, the drive shaft appears "just when" or the sound is messy. When the car backs up on the gentle slope, the intermittent sound of "Grap Paap" can indicate that the needle roller is broken or broken, and the needle roller bearing should be replaced.

3. When the car starts or changes gears, the drive shaft has obvious metal collision sound, and the low speed gear is more obvious than the high speed gear. Most of them are caused by the decrease of the interference fit between the inner ring of the middle support and the shaft, and the loose opening causes abnormal sound.

4. When the car starts or runs, the drive shaft always has an obvious "cracking" abnormal sound, accompanied by vibration, which indicates that the fixing bolt of the middle supporting bracket is loose and causes abnormal sound.

5. When the car is running at low speed, the drive shaft makes a clear and rhythmic metal impact sound, and there is a clear sound when the car is out of gear and sliding. The pressing force of multi-system universal joint bearing housing is too large, so that the bearing cannot rotate flexibly.

6. When the car is running, the sound of the drive shaft increases with the increase of the speed. The dull and continuous turbidity sound of the middle supporting bearing indicates that the middle supporting bearing falls apart due to excessive wear and tear.

The driving shaft of the car gives out a continuous "wow..." Sound, first of all, check whether the fastening bolts of the rubber pad ring spacer sleeve of the middle support bearing bracket are too tight or too loose (not according to the specified tightening torque requirements), so that the position of the bearing bracket deflection. The tightness of the bearing cover bolt can be adjusted to eliminate abnormal sound faults. If there is still sound after adjusting the bearing pretightness, the lubrication status of the bearing should be checked. If the bearing is poor in lubrication, the bearing should be disassembled and cleaned, and the bearing and bracket should be installed after filling with grease.

7. When the car is running, the sound of the drive shaft is disorderly and irregular, and sometimes the metal collision sound appears, which indicates that the universal joint forks at both ends of the drive shaft are not in the same plane, so that the constant speed arrangement is destroyed.

8. There is abnormal sound of the drive shaft when the car is running at high speed, and the abnormal sound of the drive shaft still exists when the car is sliding off gear. The raceway of many middle supporting bearings is damaged, or the installation position of the middle supporting bearing bracket is offset.

9. In order to further verify the correctness of the above diagnosis, you can check and shake the parts of the transmission shaft by hand when parking to see whether the installation position is correct, whether the surface of the parts is scarred, whether the fastening connection is loose, and whether the clearance is too loose or too tight.

A. After parking, release the parking brake and push the universal joint down with your hand. If there is slack, it means that the needle roller bearing of the cross shaft is slack.

B. Shake the parking brake disc back and forth by hand. If it is loose, it means that the spline of the second shaft of the transmission is loose.

C. Tight the parking brake and swing back and forth the rear flange of the middle drive shaft by hand. If there is loose, it means that the spline shaft key teeth of the middle drive shaft are loose.

D. Pull the flange of the middle drive shaft back and forth by hand. If it is loose, it means that the nut at the back end of the middle drive shaft is loose.

10. When the car is running, if there is a heavy metal knocking sound when the brake decelerates, it means that the riding nut of the rear plate spring is loose.