Disassembly/Inspection and Service
103
62 690 05 Rev. E
KohlerEngines.com
5. After installing new compression (top and middle)
rings on piston, make sure ring-to-groove side
clearance is 0.04/0.08 mm (0.0015/0.0031 in.). If
side clearance is greater than specifi ed, a new
piston must be used.
Install New Piston Rings
Piston Ring Orientation
10°
10°
F
A
B
C
D
E
A
Top Oil Ring
Rail Gap
B
Bottom Oil Ring
Rail Gap
C
Intermediate Ring
Gap
D
Oil Ring
Expander Gap
E
Top Ring Gap
F
FLY Stamp
NOTE: Rings must be installed correctly. Ring
installation instructions are usually included with
new ring sets. Follow instructions carefully. Use
a piston ring expander to install rings. Install
bottom (oil control) ring fi rst and top
compression ring last.
To install new piston rings, proceed as follows:
1. Oil control ring (bottom groove): Install expander and
then rails. Make sure ends of expander are not
overlapped.
2. Middle compression ring (center groove): Install
center ring using a piston ring installation tool. Make
sure identifi cation mark is up or colored dye stripe
(if contained), is to left of end gap.
3. Top compression ring (top groove): Install top ring
using a piston ring expander. Make sure
identifi cation mark is up or colored dye stripe
(if contained), is to left of end gap.
Remove Crankshaft
NOTE: If crankpin is reground, visually check to ensure
that fi llet 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
B
Flat Washer
C
Plug
D
Crankshaft
A
B
C
D
E
Fillet Must Blend Smoothly with Bearing Journal
Surface
F
High Point from Fillet Intersections
G
45° Minimum
H
This Fillet Area Must Be Completely Smooth
E
G
F
H
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. A replaceable bearing is used in
crankshaft bore of oil pan. Do not replace bearing unless
it shows signs of damage, or is 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.
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
Specifi cations, 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.
