Gear Grinding in Reverse with Dual-Clutch Transmission?
2 Answers
Gear grinding in reverse with a dual-clutch transmission is abnormal. It is usually caused by the clutch failing to disengage properly. Hazards of severe gear grinding in transmission: Transmission gear grinding essentially refers to the hard metal-on-metal contact between two gears. The outcome is obvious - accelerated wear on the gear crown. After prolonged and frequent occurrences, the originally right-angled gear crown becomes rounded. This leads to incomplete engagement after shifting gears, making it prone to gear disengagement with slight vibrations. At this point, a major transmission overhaul becomes necessary. When clutch gear grinding commonly occurs: It often happens when gear shifting is attempted without complete clutch disengagement. This not only produces gear noise during shifting but also easily causes gear grinding. Additionally, if the transmission lubricant contains large impurities, such as long-term wear metal shavings, these particles can get caught between meshing gears during rotation, also leading to gear grinding.
The other day when I was driving, I also heard that annoying grinding sound when shifting into reverse - that clattering noise. This is mainly an issue with the reverse gear set in dual-clutch transmissions. It's usually caused by worn synchronizers or misaligned shift forks preventing full gear engagement. Upon later inspection, I found unstable hydraulic pressure in the clutch actuator can also trigger this problem, especially when the car is warmed up. If reverse gear grinding occurs frequently, the gear edges will develop burrs, making the situation progressively worse. Don't delay - I recommend immediately reading the transmission trouble codes, and also checking the clutch clearance data and wear condition of the shift mechanism.
