C a m s h a f t and Bearings 1.7.2
DETROIT DIESEL 53
camshaft mounted on the end bearing surfaces, Run
NOTE: If a steel rod is not available, remove the
out should not exceed .002".
remaining plug as outlined in Steps "a"
through "g".
Examine both faces of the thrust washers. If either
face is scored or if the thrust washers are worn
Inspection
excessively, replace the washers. New thrust washers
are 208 " to 210" thick.
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
Also. examine the surfaces which the thrust washers
and blow out the oil gallery and the oil holes with
contact: if these surfaces are scratched but not severely
compressed air. Clean the camshaft bearings and
scored. smooth them down with an oil stone. If the
related parts with fuel oil and dry them with
score marks are too deep to be removed. or if` parts are
compressed air.
badly worn. use new parts.
Inspect the cams and journals for wear or scoring. If
The clearance between new shafts and new bearings is
the cams are scored, inspect the cam rollers as outlined
.0045" to .006" or a maximum of .008" with worn
in Section 1.2.1.
parts. Excessive clearance between the shafts and the
bearings will cause low oil pressure and excessive
Check the runout at the center bearing with the
backlash between the gears.
CAMSHAFT AND BALANCE SHAFT CYLINDER
BLOCK BORE MACHINING CHART
Bearings are available in ,010I and ,020 " undersize
for use with worn or reground shafts.
Oversize camshaft and balance shaft bearings are
available in sets. ,010 " oversize on the outside
diameter. to permit reuse of a cylinder block having
one or more scored block bearing bores. To use the
oversize bearings. the camshaft and balance shaft
block bores must be carefully line-bored (machined) to
the dimensions shown in Table 1.
TABLE 1
Fig. 4 Installing Intermediate Camshaft Bearing
SEC. 1.7.2 Page 3
August. 1972
