Timing Gear - Yanmar 3JH3E Service Manual

Chapter 2 Basic Engine
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3,4]H3(B)(C)E
7. Timing Gear
The timing gear is helical type for minimum noise and spe-
cially treated for high durability.
Fuel injection pump gear
Lubricating oil pump gear
No.
of
teeth Face width Spiral angle
Sea waler pump gear 31 12.0 right
Camshaft gear 56 18.0 left
Idle gear 43 18.0 right
Crankshaft gear
28
40.0 left
Lubricating oil pump gear 29 8.0 right
Idle gear 43 18.0 right
Fuel inJection pump gear 56 10.0 left
7-1 Inspecting the gears
(1) Inspect the gears and replace if the teeth are damaged
or worn.
(2} Measure the backlash of all gears that mesh, and
replace the meshing gears as a set if wear exceeds
the limit.
NOTE: If backlash is excessive, it will not only result in
excessive noise and gear damage, but also lead
to bad valve and fuel injection timing and a
decrease in engine performance.
Camshaft gear
Crankshaft gear
mm
Center distance Back lash
Back lash Wear limit
92.544~92.592 0.07~0.15
0.2
105.318~105.380 0.07~0.15
0.2
75.525~ 75.573 0.07~0.15
0.2
60.629~60.677 0.11 ~0.19 0.22
105.254~105.316
0.04~0.12 0.2
2-24
(3) Idling gear
The bushing is pressure fitted into the idling gear.
Measure the bushing inner diameter and the outer diam-
eter of the shaft, and replace the bushing or idling gear
shaft if the oil clearance exceeds the wear limit.
A, Band Care inscribed on the end of the idling gear.
When assembling, these marks should align with those
on the cylinder block.
Printed in Japan
HINSHI-II8009