What are the causes of abnormal noise in the transmission?
4 Answers
The causes of abnormal noise in the transmission are: 1. Wear and damage of bearings; 2. Abnormal gear meshing clearance; 3. Loose bolts on the transmission housing; 4. Metal peeling on gear tooth surfaces, broken gear teeth, or misalignment during assembly; 5. Water ingress into the transmission without timely repair; 6. Insufficient lubrication due to inadequate lubricant; 7. Long-term failure to replace transmission oil. Automatic transmission oil is generally replaced every 2 years or 40,000 to 60,000 kilometers, while manual transmissions require maintenance every 2 years or 40,000 to 60,000 kilometers. Transmission oil is a lubricant that keeps the gear system clean, ensuring the normal operation of the transmission and extending the service life of the transmission components.
Transmission noise is indeed quite annoying. Having run an auto repair shop for many years, I've encountered numerous car owners complaining about it. The root causes may include aging or insufficient internal lubricant, causing excessive friction between gears and bearings that produces noise; or worn synchronizers that make a clunking sound when shifting gears. Additionally, if the clutch or input shaft is loose, it's especially noticeable in automatic transmission vehicles. I can usually make a fairly accurate guess just by listening to the sound: a high-frequency whine likely indicates bearing issues, while a low grinding noise often means insufficient lubrication. The key is early detection and prompt action - otherwise minor issues can escalate into major repairs that cost twice as much. Regular oil level checks and timely oil changes are good preventive measures. Don't wait until problems arise to visit the repair shop.
I personally experienced a sudden abnormal noise from the transmission while driving on the highway. It sounded like metal grinding, which was terrifying. I immediately pulled over to check, and my mechanic friend said it was caused by insufficient transmission fluid or gear wear. After changing the fluid, the problem was resolved. Since then, I've learned my lesson: I change the transmission fluid every 50,000 kilometers to maintain good lubrication. I also avoid slamming the accelerator to reduce stress on the transmission. Ignoring abnormal noises can easily lead to complete transmission failure, and replacing it could cost tens of thousands of yuan—a huge loss. Don't neglect daily maintenance; just stay vigilant.
Transmission noise should never be ignored as it often serves as a safety warning signal. The abnormal sound may stem from bearing damage or synchronizer failure, which can lead to drivetrain malfunction. In severe cases, the vehicle may suddenly lose power and cause accidents. I frequently remind fellow car enthusiasts in our group: whenever you hear unusual noises, immediately slow down, pull over, and check the fluid level or visit a professional repair shop. Common causes like insufficient fluid or aging components are usually easy to fix, but prompt action is crucial. Safety comes first—never overlook it for the sake of convenience.
