SERVICE MANUAL
VALVE TRAIN - CAMSHAFT, TAPPETS & PUSH RODS
Section 4
CLEANING, INSPECTION & REPAIR
CLEANING
1.
Clean
all
parts
in
solvent
and
dry
with
compressed air.
2.
After cleaned parts are inspected, coat each with
clean
engine
oil
and
store
safely
until
reassembly.
NOTE: Do not damage the journals and lobes of the
camshaft or the teeth of the gear.
INSPECTION AND REPAIR
1.
Visually inspect the camshaft. If ANY of the
valve lobes are scuffed, scored or cracked.
2.
Inspect the journals for wear. Using
a
micrometer
measure
the
camshaft
journal
diameter to insure specifications of
57.948 mm (2.2814 inches)
57.976 mm (2.2825 inches)
is met. If the journals are worn beyond these
limits, replace the camshaft.
3.
Check camshaft lobe wear as follows:
a.
Compare lifting areas of the cam lobes with
a new camshaft. If excessive wear is
visible replace the camshaft.
b.
If a new camshaft is not available for
comparison, measure cam lobe wear with
micrometer as follows:
1.
Take a reading across (A-C, Fig. 13)
and across (B-D).
2.
Subtract (B-D) from (A-C). This will
give the cam lobe lift.
3.
Replace camshaft when cam lobe
wear limit of 0.51 mm (0.020 in) has
been reached for any lobe. (Refer to
SPECIFICATIONS in this section).
Figure 13. - Points of Measurement to Determine Cam
Lobe Wear
4.
Visually inspect thrust plate for wear, cracks and
distortion. Then, check for specified shaft end
clearance of
0.13 mm (0.005 in.)
0.33 mm (0.013 in.)
Replace thrust plate if clearance is excessive or
if plate is worn or damaged.
5.
Inspect
camshaft
drive
gear
for
worn
or
damaged teeth. If the bore of the gear is
widened by repeated pressing so a tight fit is no
longer possible, replace the gear with a new one.
(See Section 7 for installation procedure).
6.
Inspect bushings for wear. If worn, remove them
as follows and replace with new bushings.
a.
Remove the flywheel and flywheel housing.
b.
Using a Camshaft Bearing Service Set (3,
Fig. 14) with back-up nut (1) and
expanding collet (2) pull the bushings out of
the crankcase. (See tool list for tool
number).
1.
Remove the front and rear bearings first.
2.
Pull the two intermediate bearings out the
front of the crankcase.
CGES-185-3
PRINTED IN UNITED STATES OF AMERICA
Page 12
