Force the camshaft out of gear (10).
i. Remove thrust washer (12), Woodruff key (11) ,
and spacer (13) from camshaft (16). Remove gear (9)
from balance shaft (15) in a similar manner.
j. Remove end plugs (14) from the shafts to permit
cleaning of oil passages in the shafts. Drill and tap a 48-
inch hole in the end plug and using a suitable puller,
remove the end cap plug. Insert a 3/8-inch steel rod
through the shaft and drive the plug from the opposite
end of the shaft.
k. Remove idler gear outer thrust washer (17).
Slide idler gear (18) from the idler hub.
l. Remove bolt (19) and remove idler hub (20) and
inner thrust washer (21). Press bearing (22) from gear
m. If necessary, bearings (23) and (24) may be
pressed from the cylinder block.
Figure 4-15. Camshaft and balance shaft bearing
When removing bearings, be sure to note the
position of the bearings in the bore with respect
to the notch in the bearings. Replacement
c. Lubricate thrust washer (12) with clean engine oil
bearings must be installed in the same position.
and place the thrust washer over the gear end of the
camshaft and spacer.
4-29. Cleaning, Inspection and Repair
d. Start camshaft gear (10) over the end of the
camshaft with the key in shaft registering with the keyway
a. Clean all metal parts with cleaning solvent,
in the gear.
Federal Specification P-D-680, or equivalent before in-
e. With the camshaft supported in an arbor press,
place a sleeve on top of the gear and under the ram of
b. Replace all seals and gaskets.
the press. Press the gear tight against the spacer on the
c. Replace shaft end plugs.
d. Be sure oil holes in the camshaft and balance
f. Measure the clearance between the camshaft
shaft are clean.
thrust washer and the camshaft. This clearance should
e. Inspect shaft cams and journals. If they are
be between 0.008 and 0.015 inch with new parts. With
badly scored or worn, replace the shaft.
used parts, a clearance of 0.021 inch is allowable.
f. Inspect both faces of the thrust washer. Replace
g. Install weight (8) and secure with screws (7).
the washers if they are worn or scored. Inspect the
h. nstall retaining nut (4) in the camshaft by hand.
surfaces against which the thrust washers contact. If
i. Install the balance shaft gear on the balance
these surfaces are scratched, but not severely scored,
shaft in the same manner.
smooth the surface with an oil stone.
j. Lubricate the camshaft and balance shaft with
g. Inspect shaft bearings for signs of excessive
clean engine oil and slide the shaft into the cylinder
wear or scoring. Clearance between new shafts and
block. Be careful not to damage the bearings, cams and
bearings is from 0.0045 to 0.006 inch, or a maximum of
0.008 for worn parts.
h. Inspect all gears for wear, cracks, and pitting.
Make sure that the appropriate timing marks on
Replace gears with missing or broken teeth, or those
the gears are aligned.
showing signs of excessive wear.
k. Slide oil slingers (5) on the front of the shafts.
a. Refer to figure 4-14. Install intermediate bear-
l. Refer to chapter 4 and install upper front cover.
ings (24) into the camshaft bores. Then install end
m. Install thrust washer screws (7) and tighten the
bearings (23) in both the camshaft and balance shaft
screws to 30-35 ft-lb (41-47 N m).
bores. Install bearings from front to rear in the cylinder
n. Refer to chapter 4 and install the front balance
block. Refer to figure 4-15 for correct location of
o. Install gear nut retainer plates (3) and secure
b. Place rear camshaft spacer (13) over the timing
with screws (1) and lock washers (2). Tighten the screws
gear end of camshaft (16). Install Woodruff key (11).
to 35-39 ft-lb (47-53 N. m).