1. Normal wear means that in the case of good lubrication, the crankshaft bearing and the pin hole of the piston are worn due to the long use time. When abnormal noise occurs, it is often seen in the case of overhaul of the engine. Generally, it is about tens of thousands of kilometers malfunction.
2. Abnormal wear refers to the problem that the lubrication of the crankshaft bearing and the piston pin hole is abnormal when the engine oil is insufficient, and the problem of “dry research” occurs, causing abnormal noise and causing the crankshaft to be scrapped in advance.
No matter which kind of wear and tear, the crankshaft assembly can be directly repaired. Because the replacement of the crankshaft bearing and the rocker arm is unrealistic for the individual, even if it can be replaced, there is no corresponding detection means to ensure that the crankshaft diameter jump after assembly is within the qualified size range, and the effect and service life can be imagined.