Camshaft - Chevrolet Light Duty Truck 1973 Service Manual

2. Install new seal so that open end of the seal is
toward the inside of cover, and drive it into
position with Tool J-23042 (fig. 22L).
Support cover at sealing area.
CAUTIO N:
(Tool J-971 may be used as support).
Without Cover Removed
1. With crankshaft pulley and hub or damper
removed, pry old seal out of cover from the front
with a large screw driver, being careful not to
damage the seal surface on the crankshaft.
2. Install new seal so that open end of seal is toward
the inside of cover and drive it into position with
Tool J-23042 (fig. 23L).
Fig. 22L— -Installing Oil Seal (Cover Removed)
Fig. 23L—installing Oil Seal (Cover Installed)
(Typical)

Camshaft

Measuring Lobe Lift
NOTE: Procedure is similar to that used for
checking valve timing. If improper valve
operation is indicated, measure the lift of
each push rod in consecutive order and
record the readings.
1. Remove valve mechanism as outlined.
2. Position indicator with ball socket adapter (Tool
J-8520) on push rod (fig. 24L).
3. Rotate the crankshaft slowly in the direction of
rotation until the lifter is on the heel of the cam
lobe. At this point, the push rod will be in its lowest
position.
4. Set dial indicator on zero, then rotate the
Fig. 24L—Measuring Camshaft Lobe Lift
Fig. 25L—Timing Gear Alignment Marks
EN G IN E 6-33
LIGHT DUTY TRUCK SERVICE MANUAL