The standard of camshaft axial clearance is: gasoline engine is generally 0.05 ~ 0.20mm, not more than 0.25mm; diesel engine is generally 0 ~ 0.40mm, not more than 0.50mm. The axial clearance of the camshaft is guaranteed by the cooperation between the thrust surface and the camshaft bearing seat on the cylinder head. This clearance is guaranteed by the dimensional tolerance of the parts and cannot be adjusted manually.

After the camshaft journal works for a long time, the gap will increase due to wear and tear, resulting in the axial movement of the camshaft, which not only affects the normal operation of the valve train, but also affects the normal operation of the camshaft driving parts.

Check the axial clearance of the camshaft. After removing other parts of the valve transmission group, use the dial gauge probe to touch the end of the camshaft, push and pull the camshaft front and rear, and press the dial gauge vertically on the end of the camshaft to make the camshaft Axial movement, the reading of the dial indicator should be about 0.10mm, and the limit of use of the axial clearance of the camshaft is generally 0.25mm.

If the bearing clearance is too large, replace the bearing. Check and adjust the axial clearance of the camshaft positioned with the bearing cap. The engine camshaft is axially positioned on the fifth camshaft bearing, and the camshaft is axially positioned with the width of the bearing cap and the journal.