TM 5-3895-359-14&P
remaining plug as outlined in steps "a" through " "
g.
Inspection
Soak the camshaft in clean fuel oil. Then, run a wire
brush through the oil gallery to remove any foreign
material or sludge. Clean the exterior of the camshaft
and blow out the gallery and the oil holes with
compressed air. Clean the gears, camshaft hearings
and related parts with fuel oil and dry them with
compressed air.
Inspect the cams and journals for wear or scoring. If the
cams are scored, inspect the cam followers as outlined
on Page 10-2-31. Also, inspect the camshaft keyways
and threads for damage.
Fig. 9. Camshaft and Balance Shaft Journal Fillets
If there is a doubt as to the acceptability of the camshaft
Examine both faces of each camshaft rear end bearing
for further service determine the extent of cam lobe
and thrust washer. Also, examine the surfaces of each
wear as follows:
camshaft and camshaft gear which contact the thrust
washers. Replace excessively worn or scored parts.
NOTE:
Camshaft or camshaft gear thrust surfaces that are not
The camshaft can be in or out of the
scratched too severely may be smoothed down with an
engine during this inspection.
oil stone.
1. With a tapered leaf set of feeler gages (.0015 " .0100
NOTE:
") and a piece of square hard material 1/8" X 3/8 " X 1 "
If a new camshaft is to be installed,
measure the flat on the injector rise side of the cam
steam clean it to remove the rust
lobes (Fig. 8).
preventive and blow out the oil
passages with compressed air.
2. If the flats measure less than .003 " in depth and
there are no other defects the camshaft is satisfactory
New standard size-thrust washers are .120 " to .122"
for service.
thick. The clearance between the thrust washer and the
thrust shoulder of the camshaft is .004 " to .012 " with
3. A slightly worn lobe still within acceptable limits may
new parts, or a maximum of .018" with used parts.
be stoned and smoothed over with a fine crocus cloth.
Excessive clearance may be reduced by using thrust
washers which are .005 " or .010 " oversize.
Check the runout at the center bearing with the
camshaft mounted on the end bearing surfaces. Runout
When the thrust surfaces of a camshaft or balance shaft
should not exceed .002 ".
are ground undersize, special care must be taken as
follows:
1. Leave a .031 " to .094 " radius between the bearing
surface of the thrust collar shoulder and the bearing
surface of the camshaft (Fig. 9).
2. Leave a .010 " to .030 " radius between the bearing
surface of the thrust collar shoulder and the bearing
surface of the balance shaft (Fig. 9).
Use a fillet radius gage to measure the specified radii.
Fig. 8. Checking Cam Lobe Wear
10-2-110
