Kohler Command PRO CH620-CH740 Owner's Manual page 77

Oil Pump Assembly (Style A)
Oil pump is mounted inside closure plate. If service is
required, continue with Disassembly, Inspection, and
Reassembly.
Disassembly
1. Remove screws.
2. Remove oil pump assembly from closure plate.
3. Remove oil pump rotor.
4. Remove oil pickup by unhooking locking clip, and
pulling it free from oil pump body.
5. If relief valve is similar to shown, drive out pin to
remove oil pressure relief valve piston and spring.
Refer to following inspection and reassembly
procedures.
If relief valve is a one-piece style, staked to oil pump
housing removal should not be attempted, nor is
internal servicing possible. If a problem with relief
valve is encountered, oil pump should be replaced.
Inspection
Inspect oil pump housing, gear, and rotors for nicks,
burrs, wear, or any visible damage. If any parts are worn
or damaged, replace oil pump.
Inspect oil pressure relief valve piston. It should be free
of nicks or burrs.
Check spring for wear or distortion. Free length of spring
should be approximately 47.4 mm (1.8 in.). Replace
spring if it is distorted or worn.
Reassembly
1. Install pressure relief valve piston and spring.
2. Install oil pickup to oil pump body. Lubricate O-ring
with oil and make sure it remains in groove as
pickup is being installed.
3. Install rotor.
4. Install oil pump body to closure plate and secure
with screws. Torque screws as follows:
a. Install fastener into screw location 1 and lightly
tighten to position pump.
b. Install fastener into screw location 2 and fully
torque to recommended value.
c. Torque fastener in screw location 1 to
recommended value.
First Time Installation:
All Reinstallations:
5. After torquing, rotate gear and check for freedom of
movement. Make sure there is no binding. If binding
occurs, loosen screws, reposition pump, retorque
screws and recheck movement.
24 690 06 Rev. K
10.7 N·m (95 in. lb.)
6.7 N·m (60 in. lb.)
KohlerEngines.com
Disassembly/Inspection and Service
Oil Pump Assembly (Style B)
Oil pump is mounted inside closure plate. If service is
required, continue with Disassembly, Inspection, and
Reassembly.
Disassembly
1. Remove screws.
2. Lift oil pump assembly from closure plate. Remove
outer gerotor gear from closure plate.
3. Ensure ball and spring remain installed in pressure
relief hole of closure plate. If ball and spring fall out
of pressure relief hole, see reassembly for correct
installation.
4. Remove oil pump cover O-ring from groove in
closure plate.
Inspection
Inspect oil pump housing, gear, and rotors for nicks,
burrs, wear, or any visible damage. Inspect oil pump
cover O-ring for cuts, nicks, or any visible damage. If any
parts are worn or damaged, replace oil pump assembly
and/or O-ring. Check oil pickup screen for damage or
restriction, replace if necessary.
Reassembly
1. Lubricate outer gerotor gear with oil. Install outer
gerotor gear through shaft of oil pump, around inner
gerotor gear. Matching molding dots on inner and
outer gerotor gears is not necessary and will not
affect oil pump effi ciency.
2. Reinstall ball, then spring into pressure relief hole in
closure plate.
3. Reinstall O-ring into groove in closure plate; make
sure it is fully seated in groove.
4. Install oil pump inserting center shaft into
corresponding recess in closure plate. Apply
consistent downward pressure to oil pump cover,
compressing oil pressure relief spring and start
screws. Secure oil pump by torquing screws (in no
specifi c sequence) to 9.0 N·m (80 in. lb.).
5. After torquing, rotate gear and check for freedom of
movement. Make sure there is no binding. If binding
occurs, loosen screws, reposition pump, retorque
screws and recheck movement.
Remove Camshaft
Remove camshaft and shim.
Inspection and Service
NOTE: To prevent repeat failures, camshaft and
crankshaft should always be replaced as a set.
Check lobes of camshaft for wear or damage. See
Specifi cations for minimum lift tolerance. Inspect
cam gear for badly worn, chipped or missing teeth.
Replacement of camshaft will be necessary if any of
these conditions exist.
69