What is the reason for the noise when the Aoling Express shifts to third gear?
3 Answers
Aoling Express shifting to third gear produces noise for the following reasons: Automatic transmission water ingress not repaired in time: If not repaired in time, over time it may induce a series of problems, such as oil leakage, abnormal noise, "jerking" and other fault phenomena. By then, the repair cost for the automatic transmission will increase by 4 to 6 times compared to earlier repairs. Long-term failure to replace automatic transmission fluid: The automatic transmission fluid becomes thick. If it loses its effectiveness due to prolonged use, components will rub directly without a protective layer, thereby exacerbating the wear of mechanical parts. In severe cases, it may damage components such as the automatic transmission planetary gear set and differential, and the damage to internal parts will cause abnormal noise in the automatic transmission. Use of inferior transmission fluid: Because of the poor temperature resistance of low-quality or counterfeit transmission fluid, it is prone to oxidation, producing sludge and residues that clog the automatic transmission filter and lubrication channels, increasing friction between internal components of the automatic transmission, which may lead to abnormal noise in the vehicle.
I've been driving for over a decade and have dealt with light trucks like Aoling Express quite often. That abnormal noise in third gear is most likely a synchronizer issue. When the synchronizer rings in the transmission wear out, you'll hear that clunking sound during gear engagement. I've encountered similar situations before - cold starts would bring vibration during gear shifts, which slightly improved after the vehicle warmed up. I'd suggest first checking if the transmission fluid level is adequate and whether the oil has turned black or degraded. If the gearshift feels noticeably rougher, it's basically time to replace the synchronizer. Don't delay fixing this kind of problem - last year my neighbor put off repairs until the third gear teeth got completely worn down, ending up with an 8,000+ yuan transmission overhaul.
Last time I worked on an Aoling Express with the same issue. The mechanic showed me the worn synchronizer ring removed from the transmission - the brass material had grooves worn into it. This abnormal noise typically occurs as a 'click' sound when shifting into third gear, and in severe cases may be accompanied by gear lever vibration. Besides synchronizer issues, incomplete clutch disengagement can also cause gear grinding noise - you can try depressing the clutch for 20 seconds before shifting. If it's a worn universal joint on the rear axle driveshaft, the noise will occur during acceleration/deceleration, but gear-related noises should focus on transmission inspection. Recommend using a diagnostic tool to read fault codes, and also check if the shift cable is sticking.