What Causes a Gearbox to Fail?
3 Answers
Automobile gearbox damage is caused by aging seals, poor sealing, and improper operation can also lead to transmission failure. The symptoms of a damaged car gearbox are as follows: Engine Stalls When Shifting: After starting the car, shifting from P or N to other gears causes the engine to stall. Vehicle Does Not Move When in Gear: After starting the car, when shifting to D or R, the vehicle shows no response after releasing the brake and does not move forward. Similarly, when shifting to 1st gear and releasing the clutch, the vehicle does not drive. Transmission Locked in Gear: During normal driving, when accelerating, the engine RPM is high but the vehicle speed increases very slowly. When braking, the speed drops to a certain point but does not decrease further. When shifting, it is found that the transmission is stuck in one gear and cannot shift up or down, meaning the transmission is locked in one gear and no longer shifts.
Once I encountered this issue where the car's transmission suddenly got stuck on the highway, and the reasons can vary. Long-term use leading to internal component wear is the main cause, such as aging gears and bearings. If the transmission oil isn't replaced in time, deteriorated oil quality can cause insufficient lubrication. My friend's car had this problem because impurities in the oil clogged the oil passages. Driving habits are also crucial; shifting too aggressively or running at high RPMs in low gear accelerates component fatigue. Additionally, frequent driving in harsh road conditions can allow dust to enter and affect internal cleanliness. Regular inspections and oil changes can prevent major issues—I recommend changing the oil every two years. If you frequently tow loads, extra care is needed to avoid overheating and damaging the transmission. Overall, combining maintenance with careful driving can extend the transmission's lifespan.
Gearbox failures often stem from lubrication issues, such as insufficient oil or excessively high oil temperatures causing malfunctions. When I drove a manual transmission, I once encountered difficulty shifting gears due to low oil levels. Incorrect operation is another factor—some drivers habitually floor the throttle before shifting, which can damage the synchronizer. Manufacturing defects are rare, but newly purchased vehicles may occasionally have assembly flaws. I've heard that contaminated or unfiltered transmission oil accelerates wear. Poor cooling system performance, like a faulty fan, can also lead to gearbox overheating. Remember to avoid prolonged uphill driving or sudden acceleration. Address any issues promptly before complete failure occurs, as repairs can be extremely costly.
