As we all know, trucks have three major powertrains, namely the engine, gearbox and axle. Compared with the engine and gearbox, the axle has the lowest technical difficulty, but it is also the place where the most failures occur. There are no more than three common failure modes for truck drive axle final drive assembly: abnormal noise, high temperature and oil leakage.
Abnormal sound of main reducer assembly
1. When stepping on the accelerator to climb a slope or accelerate, the vehicle will make a “buzzing” sound. This is because the meshing marks of the active bevel gear and the passive bevel gear of the axle are not suitable. In layman’s terms, the two gears are not accurate. engage in place.
At this time, when the main reducer assembly of the axle is disassembled, it can be found that the concave tooth surface of the passive bevel gear (also called the front surface) will have relatively obvious high points, wear marks, and serious steps will appear. At this time, replacing the pair of basin angle gears can solve the problem.
2. When the brakes are applied to decelerate, the vehicle will also make a “buzzing” sound, which is also due to the inappropriate meshing marks of the active bevel gear and the passive bevel gear.
But the difference from the first one is that when the main reducer is opened, it can be found that this time, the convex tooth surface (also called the reverse surface) of the passive bevel gear has obvious high points and wear marks, and serious steps will appear. . At this time, the problem can be solved by replacing the pair of basin angle gears.
3. When the vehicle accelerates, the sound of “clang, clang, clang” is heard from the axle bag, also called knocking sound. This is because the gap between the active bevel gear and the passive bevel gear is too large, and there will be a sound caused by the impact between the gears.
Under normal circumstances, when you hear a more obvious knocking sound, you will find it when you disassemble the main reducer. The gear has problems such as tooth grinding, tooth surface peeling, and pitting. At this time, the old method is still to replace the gear to solve the problem.
4. If the vehicle makes harsh noises during normal driving: this is due to failures such as pitting, peeling, wear, falling apart, and ablation of the bearings in the main reducer, then we need to replace the corresponding bearings up.
5. If the vehicle has no problems during normal straight-line driving, but it makes abnormal noise when turning, then we can preliminarily judge that this should be due to damage to the differential.
At this time, disassemble the differential in the main reducer, check the housing, cross shaft, spherical gasket, gear and other parts in turn, and replace the damaged parts.