Fast Transmission Noise and Vibration Problems

There is a rattling sound when starting the plate shift lever

1. Fork wear
2. The gear is affected by the shaft distortion and leaves the opposite tooth position
3. The intermediate shaft brake does not work
4. Link movement disorder
5. Improper adjustment of connecting rod
6. The inner bushing of the shift mechanism housing is worn
7. Improper clutch adjustment

Loud noise

1. The gear is affected by the shaft twist and leaves the opposite tooth position
2. The gear has cracks or burrs on the teeth
3. The tolerance of the main shaft gear is too large
4. The inner ring of the front bearing of the intermediate shaft of the auxiliary box falls off
5. Bearing damage
6. The oil level is too low
7. Poor quality of lubricating oil
8. Oil change is not timely
9. Mixed use of different oils

Gears rattle when idling

1. The tolerance of the main shaft gear is too large
2. The engine is not running smoothly

Big vibration

1. Engine support damage
2. The tightening torque of the output shaft nut is not enough
3. Improper installation of the drive shaft
4. Suspension wear

There is a certain amount of noise when the transmission is in normal operation. However, if the noise is too loud or abnormal, such as roaring, squealing, etc., it indicates that there is some problem with the transmission. These noises may be caused by the transmission itself, or may be generated by noises from other parts of the vehicle that are transmitted to the transmission and amplified by it.

The noise of the transmission itself

1. Knocking sound
(1) Caused by the collision of the tooth surface of the inner gear of the transmission. It can be identified by the bright spots that appear after the tooth surface is strongly pressed and ground. Generally, this noise is more pronounced when the gear is under load. Therefore, when a certain gear is engaged, noise is generated, indicating that there is a problem with the gear of this gear. Such bumps can be smoothed with a whetstone or a hand wheel.

(2) If the balls or rollers of the bearing are damaged, the raceway will be pitted and peeled off, and noise will be generated at low speeds in each gear.

(3) If the gear is subjected to impact load or cracks occur during the assembly process, a knocking sound will be produced at low speed and a squealing sound will be produced at high speed.

2. Scream

(1) Caused by normal wear and tear of gears. Including pitting that develops after long-term use, which produces a squealing sound before damage.
(2) Caused by improper gear meshing. It can be identified by the uneven wear of the tooth surface.
(3) After the bearing is preloaded, if the axial and radial clearances are too small, squeals will also be generated.

3. The roar

Caused by the “tooth” error. The roaring noise can be caused by incorrect “tooth alignment” when the transmission is reassembled, or due to gears turning on the countershaft.

4. Clicking sound

The axial clearance of the countershaft and the main shaft bearing is too large, and a rattling sound will be generated when the torque changes direction. If the radial clearance of the countershaft bearing is too large, the center distance of the shaft will increase, which will cause the load to act on the tooth top, which may also cause the gear teeth to break.

Noise from other parts of the vehicle

1. The engine does not run smoothly at idle speed;
2. The working noise of the engine;
3. The spring or rubber block of the clutch driven plate loses its vibration damping effect due to wear and tear;
4. The drive shaft is unbalanced;
5. The working angles of the universal joints are not equal;
6. The universal joint cross shaft is worn;
7. The intermediate support bearing of the drive shaft is loose or worn;
8. The tooth surface of the drive axle basin angle gear is worn or pitted, and the rear axle gear is damaged;
9. Wheel imbalance;
10. The bearing of the leaf spring lifting lug is worn;
11. The riding bolt is loose;
12. The brake hub is warped or unbalanced.