Foreword. When it comes to word "anomalous noise", most older drivers are very sensitive. When you drive or park your car and then hear a creaking sound, you can't find it when you're looking. In fact, in this time we must seriously consider reasons.
First of all, you need to talk about wrong driving manners, do not drive in neutral, because engine speed does not match speed of car. This will speed up life of a worn gearbox, especially at such high speeds where abnormal noises can easily break gears.
An abnormal noise is heard when coasting in neutral and it is suspected that there is a problem with transmission shaft. Check drive shaft to make sure cross member is not loose, counterweight on drive shaft has fallen off, etc. It is recommended to check if sound is coming from suspension or chassis.
Chassis rattling after shifting from high to neutral?
Generally, truck loses neutral gear at high speed and chassis makes noise, which is mainly caused by a large gap between drive shaft and rear gear. You can first check if there is enough oil in reverse gear, and then tighten it. If cardan shaft is still making noise, you should go to a repair shop to replace it. The wheel teeth, and truck chassis is making abnormal noises. It's better not to delay repair earlier and be sure. Otherwise, when you load heavy loads, drive shaft will fall, gear bag will block and shaft will break, then it will be a big problem..
Skills to eliminate abnormal noise from an automobile engine and rear axle
First, drive car on a flat road for a certain mileage so that rear axle operating temperature rises to normal, then, when car makes extraneous sounds, fix speed, after parking, put gearbox in neutral, and then slow down Slowly accelerate until speed engine does not match speed of car when there is an abnormal sound, and observe if there is any abnormal sound Repeat several times to determine if abnormal sound is caused by exhaust or abnormal engine condition.
The difference between car tire noise and rear axle noise
Tire noise is road dependent, but rear axle noise is not. When vehicle speed is below 48 km/h, rear axle noise disappears, but tire noise remains. When car is moving and coasting, noise of tires is same, but noise of rear axle is different.
The difference between abnormal noise of an automobile wheel hub bearing and abnormal noise of a rear axle
When car is moving and sliding, noise of front wheel bearings remains unchanged. By maintaining a constant vehicle speed and braking lightly, load on wheel bearings can be reduced so that noise can be reduced. be attenuated, and source of noise can be located.
When vehicle speed exceeds 48 km/h, if rear axle is not severely damaged, rear wheel bearing noise is generally rare, and a rusty rear wheel bearing makes a "whipping" sound.
Recognizing abnormal noise between drive taper bearing and automotive gear differential bearing
Reducer bearings typically produce a harsh "rumble" or "crack" with a steady rhythm that changes with vehicle speed.
Bevel gear front bearing noise is louder when vehicle is sliding, and rear bearing noise is louder when vehicle is moving.
Differential bearing noise is usually a constant harshness, but its beating is much more moderate than bevel gear bearing noise.
Remove noise from rear axle reduction gear
During normal straight-line motion, no noise is heard because side gears of differential and planetary gears have little relative motion.
When car is running, reason for abnormal sound of rear axle reduction gear is mainly due to poor lubrication, which will cause wear of reduction gear. If abnormal sound can be heard at various slip speeds, then it is caused by loosening of reduction drive gear nut.
A knock is heard in rear axle at low speed, and when accelerating or braking, a particularly dull abnormal sound is heard. The cause of above error can be found by one or more of following symptoms:
①The gap between differential journal and differential housing is not correct.
② Incorrect interaction between differential cross shaft journal and differential housing.
③ The backlash of side shaft spline gear and differential side shaft gear keyway is incorrect.
④The engagement gap between differential axle gear and planetary gear is not correct.
⑤ Incorrect backlash in engagement of drive and driven gears of differential cone.
⑥The thrust washer is worn out.
When vehicle is running, abnormal rear axle noise is caused by incorrect gear engagement, improper differential bearing preload adjustment, or both. When eliminating extraneous noise, it is necessary to disassemble and check gap between differential gear and gear of reducer, preload of tapered bearing of drive gear of reducer and traces of contact of reducer gear.