Kohler command pro CH940 Service Manual page 66

Disassembly/Inspection and Service
Remove Crankshaft
NOTE: If crankpin is reground, visually check to ensure
that fillet blends smoothly with crankpin surface.
Carefully pull crankshaft from crankcase. Note thrust
washers and shims if used.
Inspection and Service
Crankshaft Components and Details
A
Self-Tapping Screw
C Plug
G
E
Fillet Must Blend Smoothly with Bearing Journal
E
F High Point from Fillet Intersections
G
H This Fillet Area Must Be Completely Smooth
Inspect gear teeth of crankshaft. If teeth are badly worn,
chipped, or some are missing, replacement of crankshaft
will be necessary.
Inspect crankshaft bearing surfaces for scoring,
grooving, etc. Replaceable bearing is used in crankshaft
bore of closure plate and/or crankcase. Do not replace
bearing unless they show signs of damage or are out of
running clearance 0.040/0.167 mm (0.0015/0.0065 in.).
If crankshaft turns easily, without noise, and there is no
evidence of scoring, grooving, etc., on races or bearing
surfaces, bearing can be reused.
Inspect crankshaft keyways. If they are worn or chipped,
replacement of crankshaft will be necessary.
66
A
B
C
D
B
Flat Washer
D Crankshaft
F
H
Surface
45° Minimum
Inspect crankpin for score marks or metallic pickup.
Slight score marks can be cleaned with crocus cloth
soaked in oil. If wear limits, as stated in Clearance
Specifications, are exceeded, it will be necessary to
replace crankshaft or regrind crankpin to 0.25 mm
(0.010 in.) undersize. If reground, a 0.25 mm (0.010 in.)
undersize connecting rod (big end) must then be used to
achieve proper running clearance. Measure crankpin for
size, taper, and out-of-round.
Clearance Specifications-Connecting Rod Journal
O.D. - New
O.D. - Max. Wear Limit
Max. Taper
Max. Out-of-Round
Width
Connecting rod journal can be ground 1 size under.
When grinding a crankshaft, grinding stone deposits
can get caught in oil passages, which could cause
severe engine damage. Removing crankpin plug when
crankshaft is ground provides easy access for removing
any grinding deposits that may collect in oil passages.
Use following procedure to remove and replace plug.
Remove Crankshaft Plug
1. Drill a 3/16 in. hole through plug in crankshaft.
2. Thread a 3/4 in. or 1 in. long self-tapping screw with
a flat washer into drilled hole. Flat washer must be
large enough to seat against shoulder of plug bore.
3. Tighten self-tapping screw until it draws plug out of
crankshaft.
Install New Crankshaft Plug
Use 1 single cylinder camshaft pin, as a driver and tap
plug into plug bore until it seats at bottom of bore. Make
sure plug is tapped in evenly to prevent leakage.
Remove Governor Gear Assembly
Governor gear is held onto shaft by small molded tabs
in gear. When gear is removed from shaft, these tabs
are destroyed and gear must be replaced. Therefore,
remove gear only if absolutely necessary. If governor
cross shaft, yoke, or gear condition does not require
removal, governor gear may be left in place. If removal is
necessary, perform as follows:
1. Remove locking tab thrust washer and note
orientation.
2. Using a screwdriver, carefully pry upward to unseat
governor gear assembly from governor gear shaft.
Remove regulating pin and governor gear assembly.
3. Inspect governor gear shaft for wear or damage.
Remove shaft only if replacement is needed.
Inspection
Governor gear is located within crankcase. Inspect
governor gear teeth. Replace gear if it is worn, chipped,
or if any teeth are missing. Inspect governor weights.
They should move freely in governor gear.
KohlerEngines.com
43.982/44.000 mm
(1.731/1.732 in.)
43.97 mm (1.731 in.)
0.018 mm (0.0007 in.)
0.025 mm (0.0010 in.)
53.00/53.09 mm
(2.0866/2.0901 in.)
62 690 01 Rev. J