Engine crankshaft axial clearance

The axial clearance of the engine crankshaft is also known as the end clearance of the crankshaft. During the operation of the engine, too small a gap can cause the parts to expand due to heat and become stuck; Excessive clearance will cause axial movement of the crankshaft, accelerate cylinder wear, and affect the valve timing and normal operation of the clutch. Therefore, during engine maintenance, the size of this gap should be checked and adjusted until it is appropriate.

The axial clearance of the crankshaft refers to the clearance between the bearing thrust end face and the journal positioning shoulder. If the gap is too small, it will cause the machine to expand and get stuck; Excessive clearance and forward and backward movement will cause abnormal wear to the components of the piston connecting rod group, and the surface of the thrust bearing bush or thrust washer will gradually wear, causing the clearance to change and forming axial displacement. Therefore, when assembling the crankshaft, the axial clearance of the crankshaft should be checked.

During inspection, first fit the crankshaft positioning shoulder against one side of the bearing's thrust end face, press the crankshaft towards the rear end with a crowbar, and then use a feeler gauge to measure between the crankshaft arm and the thrust bearing shell or thrust washer.

The axial clearance of the crankshaft is generally 0.05-10 18mm。 If the axial clearance is too large or too small, replace or repair the thrust bearing or thrust washer for adjustment.