Reassembly Of Oil Pump - Yanmar 4TNV98 Service Manual

Outer Rotor to Inner Rotor Tip Clearance
Determine the outer rotor to inner rotor tip clearance.
Insert a feeler gauge between the top of an inner
rotor tooth (Figure 9-18, (1)) and the top of an outer
rotor tooth (Figure 9-18, (2)) and measure the
clearance.
Figure 9-18
Record the measurement(s) and see Outer Rotor to
Inner Rotor Tip Clearance on page 216 for the
service limits.
Check Outer Rotor Side Clearance
Determine the side clearance of the outer rotor
across the pump cavity. Measure the depression
using a depth micrometer (Figure 9-19, (1)).
Figure 9-19
Record the measurement(s) and see Check Outer
Rotor Side Clearance on page 217 for the service
limits.
4TNV98 & 4TNE98 Diesel Engine
Check Rotor Shaft Clearance
Determine the rotor shaft clearance. Measure the
outside diameter of the rotor shaft (Figure 9-20, (1))
and the bore diameter in the gear case housing
(Figure 9-20, (2)).
Calculate the difference between the two
measurements to determine the clearance.
Record the measurement(s) and see Rotor Shaft
Clearance on page 215 for the service limits.

Reassembly of Oil Pump

1. Lubricate the outer rotor and pump bore in the
gear case with clean engine oil.
2. Reinstall the outer rotor in the gear case housing.
The punch mark (Figure 9-21, (1)) on the end of
the outer rotor must face away from the gear case
housing (Figure 9-21, (2)).
217
Figure 9-20
Figure 9-21
Section 6. Lubrication System