III. Crankshaft Thrust Washer
The crankshaft axial positioning of MR479Q engine adopts the structural form of two-half-circle thrust washer. Crankshaft
thrust washer is also of a steel-backed-wear-reducing-layer structure. Steel-backed material is 08F, wear-reducing layer
material is of high-tin aluminum alloy. The crankshaft thrust washer is 2.5 thick. On the working faces of two thrust
washers, oil holes are milled respectively. Crankshaft thrust washer is positioned by way of locating tongue.
IV. Flywheel
The role of flywheel is to restrict the revolving unevenness with the flywheel, storing part of the energy done by the engine
so as to ensure that incoming air compression and exhaust stroke run smoothly and overcome the short time overload. The
start of the end face of engine can serve as an active friction face to export the power.
Engine flywheel is made from gray cast iron with 254mm in diameter. The flywheel is thick outside and thin inside to reduce
its weight. The outmost of the flywheel end face has 6 mounting holes for M8-6H clutch and 3 holes (?8 ) for dowel
pin holes. There are 5 mounting holes for flywheel and 1 hole for positioning the flywheel. Revolving-speed toothed disc
installed on the outer peripheral of flywheel is interference fit with the flywheel. The peripheral is positioned by dowel pin.
There are totally (60-2) teeth on revolving-speed toothed disc, and there is a “T” mark on the disc end face. The “T” mark
corresponds to the locating hole and crankshaft 1.4 crank plane. Counterclockwise, there is an absence of 2 teeth in the
part of 1320 in front of “T”. Because of the speed sensor installed in the centerline of cylinder block, when speed sensor
corresponds to the missing teeth, it has created a pulse signal of speed sensor to ECU . In the part of 1140 in front of “T”,
the falling edge of the teeth starts to trigger the controller to make the timer work.
1. Disassembly for Inspection
1. Detaching of flywheel
Before disassembly, use a dial gauge to check the slanting degree (as shown in Fig. 188). Disassemble the rotation speed
sensor and its support. Detach 6 bolts and the flywheel.
2. Disassembly of crankshaft
(1) Check the radial clearance of crankshaft
Section 2 Disassembly & Maintenance of
Crank Mechanism
Fig. 188 Check the Slanting Degree
Fig. 189 Test the Radial clearance of Crankshaft
-0.03
-0.06
+0.015
0
78
Summary of Contents for JL481Q
Page 1: ......
Page 9: ...5 Fig 3 Components Assembly Drawing of MR479Q MR479QA Engine ...
Page 10: ...6 Fig 4 MR479Q MR479QA Engine and Its Power System ...
Page 11: ...7 Fig 5 Assembly Drawing of Engine and Its Auxiliaries MR479Q MR479QA ...
Page 12: ...8 Fig 6 Electronic Control Fuel Injection System in Engine MR479Q MR479QA ...
Page 13: ...9 Fig 7 Front view of Engine JL481Q MR481QA ...
Page 14: ...10 Fig 8 Sectional elevation of Engine JL481Q MR481QA ...
Page 15: ...11 Fig 9 Electronic Control Fuel Injection System in Engine JL481Q MR481QA ...