Mitsubishi S4Q, User Manual

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49 / 174 Service Manual Mitsubishi SQ-Series diesel engines
Version 08/2004
TIMING GEARS, CAMSHAFT AND OIL
PAN
ENGLISH
ENGINE MAIN PARTS
9.2.1 Crankshaft pulley
Check the V-belt groove for wear. Wrap a new belt
around the pulley, pressing it in the groove as far as it
goes, and see if the top surface of the belt is above the
top of the pulley.
If the top surface of the belt (or the belts for the pulleys
having two or more grooves) is uniformly above the top
of the pulley all the way around, it is not necessary to
replace the pulley.
If the top surface of the belt sinks into the groove more
than 1.6 mm [0.063 in.], replace the pulley.
9.2.2 Idler gear
1. Checking clearance between idler gear and shaft
Measure the inside diameter of the idler gear and
the diameter of the shaft, as shown in the illustra-
tion, to check the clearance. If the clearance
exceeds the service limit, replace the gear or shaft
whichever is badly worn.
Unit: mm [in.]
2. Replacing idler gear bushing
1) To replace the bushing, use idler gear bushing
installer (30691–51900).
2) When installing a replacement bushing, press
it into position until its end is flush with the end
of the gear boss.
3) After installing the bushing, finish its inside
diameter to 36 (1.42) H7 ( ) 0.8 Ra.
Figure 71 Wear limit of V-belt groove of pulley
1.6 mm [0.063 in.]
Figure 72 Measuring idler gear and shaft
Item
Assembly
Standard
Service
Limit
Clearance between
idler gear and shaft 0.025 to 0.075
[0.0010 to 0.0030]
0.100
[0.0039]
Figure 73 Replacing idler gear bushing
Idler gear
bushing
installer
+0.025
0
+0.0098
0