Mack E7 Service Manual page 149

5-101.bk Page 59 Friday, March 17, 2006 11:05 AM
6. Insert pumping gear in housing and check
for free play by spinning. If any binding
occurs, check housing and gear teeth for
burrs, nicks, or other damage. Replace as
necessary.
Before proceeding with assembly, check end
clearance, side clearance, and backlash of drive
gears as follows.
END CLEARANCE CHECK
Refer to Figure 5-71.
1. Low Limit — Place a straightedge across
face of gears and run a 0.001-inch
(0.025 mm) thickness gauge under
straightedge. Gauge should move freely
without binding. If binding occurs, check
gears for nicks or burrs. Replace as
necessary.
2. High Limit — With straightedge in place (as
in step 1), run a 0.007-inch (0.178 mm)
thickness gauge under straightedge. Gauge
should be very tight. If gauge moves freely,
replace gears.
200 BENCH PROCEDURES
Figure 5-71 — Oil Pump Driving/Idler Gear Assembly
End Clearance Check
1. Thickness gauge 3. Pump driving gear
2. Straightedge 4. Pump driven gear
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