Weichai America Corp.
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4.
Loose-fit rocker seat on cylinder cover with hexagon bolts;
5.
Install valve pushrod, refer to assembly of valve pushrod for details;
6.
Pre-tighten rocker seat, align rocker adjusting screw socket head to valve pushrod round head,
tighten the hexagon bolts to 40~45Nm.
Inspection and maintenance valve lash
1.
Rotate the crankshaft until phase pointer points at 0 tick on phase plate, observe and make
sure 0 tick of crankshaft timing gear is engaged with 0 tick of camshaft gear. Then adjust
valve clearance of No. 1-2-3-6-7-10 rocker (count from the front end), intake valve
adjustment: firstly fill in a 0.2mm plug gauge, and tighten the nuts with torque spanner to
20±5Nm, pull out the gauge (make sure the gauge can be easily pulled out), and check the
clearance with a 0.25mm plug gauge (make sure the gauge cannot get through), adjusting of
intake valve is finished. Exhaust valve adjustment: firstly fill in a 0.3mm plug gauge, and
tighten the nuts with torque spanner to 20±5Nm, pull out the gauge (make sure the gauge can
be easily pulled out), and check the clearance with a 0.35mm plug gauge (make sure the
gauge cannot get through), adjusting of exhaust valve is finished.
2.
Further rotate crankshaft until phase pointer points at 0 tick on phase plate, observe and make
sure 0 tick of crankshaft timing gear is engaged with the symmetry point of 0 tick (180º) on
camshaft gear. Then adjust valve clearance of No. 4-5-8-9-11-12 rocker (count from the front
end), refer to 1 for adjusting method.
4.6.4 Rocker and Rocker Shaft Inspection and Maintenance
1.
Clean the rocker and check for any cracks.
2.
Check the rocker inner hole for abrasion and scratches and measure its diameter.
3.
Check the rocker adjusting screw and the other end arc surface for abrasion.
4.
Check to ensure that all oil galleries are smooth.
5.
Measure the diameter of rocker inner hole and rocker shaft. Calculate the fitting clearance.
