Gear System - FAW Jiefang Automotive 485 Operation & Maintenance Manual

1. Timing gear
Gearing system consists of timing gear and timing idle gear on crankshaft, timing gear on
camshaft, and timing gear and timing gear seat etc on fuel-injection pump.
Each timing gear is marked with timing-mark. When fitting the gear, marks should correctly
be followed where is engaged., so as to ensure correct moving relationship between moving parts.
See Fig. 9.
2. Mounting/dismounting of the gears
Mounting/dismounting of the timing gear on crankshaft needs special tools. Timing gear on
camshaft can be pulled out by a gearwheel-puller, or be pushed up by a pressing machine.
Clearance fit is adopted between the timing idle gear and engine body, be secured with bolts.
Mounting of gear of fuel-injection pump: Gear of fuel-injection pump is fitted on the coupling
disc of the advancer. Before dismounting the timing gear of fuel-injection pump, the cover of
advancer should be removed, then the nut(s) on shaft of fuel-injection pump should be loosened
VI. Gear system
Fig. 9 Timing gear system assembly
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