Remove the driven gear (item 11) and the
drive gear and shaft (item,12). Inspect for wear. Any
wear on gear hubs, at the drive coupling or in the seal
areas detectable by touch, or In excess of .002 inch
(0,051 mm) necessitates replacement. Any evidence of
scoring, grooving or burring of outside diameter of teeth
or teeth surfaces requires replacement. Wear in the
Replacement can only be made by drive and driven
Pry the thrust plates (item 5) from the shaft
and cover (item 9) and port end cover (item 1) with a
screw driver. Avoid distorting the thrust plate. Remove
and discard all rubber pocket seals (item 4) and gasket
seals (item 6).
Gear Housing Removal
Lift or pry off the gear housing (item 7). Be
careful not to damage machined surfaces. Inspect the
gear housing for damage or wear. Wear In excess of
.005 inch (0,127 mm) cut-out necessitates replacement
of the housing. Place a straight edge across the
housing bore. If you can slip a .005 inch (0,127 mm)
feeler gauge under the straight edge, replace the gear
housing. Excessive cut-out in a short time period
indicates excessive pressure or oil contamination.
Where the cut-out Is moderate, .005 inch (0,127 mm) or
less, gear housing may be flipped over and reused.
Thrust Plate Removal
The thrust plates seal the gear section at the
sides of the gears. Wear here will allow internal
slippage, that is, oil will bypass within the pump.
Maximum allowable wear is .002 inch (0,051 mm).
Replace the thrust plates If they are scored, eroded or
pitted. Erosion In the center area where the gears mesh
discolored thrust plates. Pitting is a sign of cavitation or