Manual transmission abnormal sound cause judgment
Abnormal sound of transmission gear is usually caused by low transmission oil level or deterioration, too large or too small gear meshing clearance, and poor gear meshing.
When the mesh clearance is too large
When the driving gear rotates, it strikes the passive gear and makes a banging sound, which is usually more serious with the higher the transmission temperature.
The mesh clearance is too small
The noise is usually continuous, some are more uniform, some are not uniform, and the faster the speed, the more serious the noise, and often make the transmission of the oil overheating.
The gear tooth surface is damaged
This sound is uneven, rhythmic, and the greater the throttle, the greater the sound, serious will feel the vibration of the transmission.
Transmission gear noise is caused by low gear precision when the transmission is manufactured, some are caused by replacing the new gear with the original old gear when the car is repaired or by bad meshing due to improper operation. This noise is caused by the faster the speed, the greater the noise, the higher the temperature, the thinner the lubricating oil, the worse the noise, and the noise will gradually reduce or disappear after running in.
The rolling bearing rings
It is usually caused by excessive bearing clearance, or the loose fit between the inner bearing ring and the shaft and the outer seat ring and the transmission housing. If the bearing ball has cracks or spots, it usually makes a crushing noise.
When diagnosing the cause of abnormal sound fault of the transmission, the law of good sound occurrence should be distinguished first, and the possible fault causes and maintenance measures should be further judged according to the situation.
There was a whoosh when the transmission shifted
Every time you change gears, it sounds like the clutch is not stepped on to the end, in fact, it has been stepped on to the end, and every gear is so, but it does not ring when it is turned off! The reason for this is obvious: the clutch is really not fully detached.
Solution: Adjust the clutch pedal, adjust the clutch pump push, if there is still no effect, it is recommended to replace the pressure plate.
Idle manual transmission abnormal sound
If the car is idling or driving, there is an abnormal sound in the transmission part of the cab.
The possible reasons are: the transmission oil is missing or the oil is bad; Transmission bearing wear, loose or damaged bearings; Transmission shaft is bent; Gear meshing is not normal, meshing clearance is too large or too small; Gear tooth surface metal spalling, tooth fracture or repair assembly dislocation; The gear shift lever 勹 the groove of the gear shift fork is loose.
Solution: There is metal dry friction sound in the car, and the transmission shell feels hot with the hand, which is caused by the sound caused by the lack of lubricating oil or lubricating oil deterioration, should be refueled or checked the oil quality, and replaced if necessary.
Manual transmission has abnormal noise in neutral
After stepping on the clutch pedal, the sound is eliminated, which is generally worn, loose or often engaged gear ring on the front and rear bearings of the transmission shaft. If it is changed into any pinch, it is mostly the rear bearing of the second shaft, and the bearings that are seriously loose or damaged should be repaired or replaced.
Manual transmission abnormal noise at low speed
When the vehicle is driving at low speed, there is a abnormal sound of the manual transmission, a rhythmic noise of "angry, ga, ga", and when the speed increases, it becomes a more chaotic gear bump and the gear shift is also loud, which may be caused by the poor meshing of the gear in the transmission, such as the sound is slight and more uniform, it can continue to run in and use, such as more serious and uneven, it should be removed for inspection. It should be readjusted or replaced if necessary.
Acceleration is not loud, deceleration is loud
At a certain gear, such as 3rd gear, release the accelerator pedal and you will hear a humming sound, which disappears as soon as you accelerate! In this case, in serious cases, it is generally accompanied by abnormal sound when hanging from 2 gear into 3 gear, and the reason for this situation is also obvious: the kneading ring of the synchronizer is damaged, and there are 3 to 4 synchronizers in a transmission, so the synchronizer assembly of the fault gear (3 gear) can be completely solved by replacing it separately.
Engine idle manual transmission abnormal sound
When the engine is idling, it makes a "ga, ga, ga" rhythmic sound, and the sound is more serious when the throttle is increased, and the transmission has a vibration phenomenon, generally due to the tooth surface spalling or tooth fracture caused by the repair assembly dislocation, gear center offset, it will also make this sound, in this case, it should be disassembled and inspected, and replaced with new parts if necessary.
Stutter, abnormal sound when accelerating
There are roughly two reasons for this :1. The clutch plate problem, the torsion spring problem, this problem, generally accompanied by the start of the car.
In a gear (such as 3 gear) when the rapid acceleration of the instant, or "clang" sound, generally caused by the synchronizer kneading sleeve and the drive gear clearance is too large.
The manual transmission makes a random sound while driving
When driving, there is a rhythm and dull sound in a gear, and the sound disappears when holding the gear shift lever by hand, which may be caused by the wear of the gear fork groove or the wear of the working face at the lower end of the gear shift lever, and should be removed, repaired or replaced. The sound is obvious after changing into a gear during driving, that is, the gear of the gear is worn too much and makes a noise, if a periodic sound is issued, it is the damage of individual gear teeth.
Abnormal noise during variable speed operation
The sudden crash sound emitted during the transmission operation may be the tooth fracture, and the transmission should be opened in time for inspection and repair or replacement.
