
1. Valve tappet (see Section 2 of Chapter 3 for reference)
Measure the tappet bore of cylinder head with a caliper and its diameter with a micrometer caliper. The actual oil film clear-
ance is deduced by subtracting the tappet diameter from the tappet bore. If the oil film clearance is bigger than the
maximum value, the tappet shall be replaced. When necessary, replace the cylinder head.
III. Valve Train Assy.
1. Check the valve stem and guide
2. Check and grind the valve
3. Check and clean the valve seat
4. Check the valve spring
IV. Service of Timing Gear, Belt and Tensioner
1. Timing belt
While servicing the timing belt, be sure not to bend, twist
or upturn it. Keep the belt away from engine oil, water or
steam. Do not make use of the belt tension when
detaching the bolts of timing pulley of camshaft.
Pay attention to direction and position when reinstalling a
timing belt undertaking detaching.Therefore, you need to
make a mark during detaching . See Fig. 202.
II. Camshaft and bearing seat
1. Check the run-out of camshaft. If the radial run-out is larger than the maximum, replace the camshaft.
2. Check the peach tip height of cam, and if not up to the standard, replace the camshaft.
3. Check the camshaft journal. If the diameter is not up to the standard, check the oil film clearance.
4. Check the cam bearing for peeling-off or scorching. If damaged, it is necessary to replace the complete set of bearing
and cylinder head.
5. Check camshaft gear spring. If the free length is not up to the standard, have the gear spring replaced.
6. Check the oil film clearance of camshaft journal, and if it is larger than the maximum value, replace camshaft. If neces-
sary, replace the complete set of bearing and cylinder head.
7. Check the axial clearance of camshaft. If it is larger than the maximum, replace the camshaft. If necessary, replace the
cylinder head.
8. Check the camshaft gear clearance. If it is larger than the maximum, replace the camshaft.
Section 4 Service of Valve Train
Fig. 202 Alignment of compression TDC mark
89
Содержание JL481Q
Страница 1: ......
Страница 9: ...5 Fig 3 Components Assembly Drawing of MR479Q MR479QA Engine ...
Страница 10: ...6 Fig 4 MR479Q MR479QA Engine and Its Power System ...
Страница 11: ...7 Fig 5 Assembly Drawing of Engine and Its Auxiliaries MR479Q MR479QA ...
Страница 12: ...8 Fig 6 Electronic Control Fuel Injection System in Engine MR479Q MR479QA ...
Страница 13: ...9 Fig 7 Front view of Engine JL481Q MR481QA ...
Страница 14: ...10 Fig 8 Sectional elevation of Engine JL481Q MR481QA ...
Страница 15: ...11 Fig 9 Electronic Control Fuel Injection System in Engine JL481Q MR481QA ...
Страница 21: ...17 Fig 13 Exterior Feature of JL481Q Engine Power Me N m Torque Pe Kw ge g kwh Fuel Consumption Ratio ...