How to Diagnose and Eliminate Abnormal Noise of Engine Gears

If you suspect that there is abnormal noise in the engine gear, you can touch the timing gear cover with a stethoscope to make the engine speed fluctuate. There is a "cough, cough" gear clearance is too large; if it is metal friction sound, it means poor lubrication and too many parts fit. Unusual friction due to tightening. There is a uniform interrupted sound at idle speed, and the sound is messy at high speed, so it is the deflection of the timing gear; at idle speed; at high speed, the sound has a different roar, so the backlash fit is too small. When the backlash of the timing gear is too small, the sound is even and can continue to be used. If the timing gear backlash is excessive, knocking at a steady speed, the timing gear should be replaced (at startup)

Slight noise is allowed when the machine speed changes).

If the axial clearance of the camshaft is too large, adjust the specified value. Camshaft flange thickness is 500.048nun, camshaft

The thickness of the diaphragm of the stop push washer is 5mm and 8:mm, and the range of its accuracy must be guaranteed.

Check the lubricating oil nozzle (that is, the nozzle), if it is blocked, you can use a pin to clear it (but not poke it big). The aperture is 0. .80mm,

Must not exceed 1mm. If the hole gets bigger, it will reduce the oil pressure.

When replacing the timing gear, replace the gear pair in pairs, check the contact surface with red paint (or red lead), and generally check the contact surface.

Check whether the contact surface is tight on one side, and check whether the backlash is even. The timing gear pair requires high precision, appropriate meshing clearance, appropriate contact clearance, appropriate contact clearance, and appropriate contact clearance.

The total length of the tooth is not less than 1/3. The contact trace must be located in the area near the pitch circle in the height direction, and its height is not small.

The tooth height is less than 1/4; the contact marks on the tooth surface shall not be less than 2.5mm from the edge