Chevrolet 10 Series 1968, Service Manual

Page: 367 / 713

ENGINE 6-20
Fig. 12 L— Instal ling O il Seal (Cover Removed)
O il Seal (Front C over)
Replacement
W ith C o v e r R e m o val
1. With cover removed, pry old seal out of cover from
the front with a large screw driver.
2. Install new seal so that open end of the seal is to­
ward the inside of cover and drive it into position
with Tool J-995 (fig. 12L).
C A U TIO N :
Support cover at sealing area. (Tool
J-971 may be used as support).
W ithout C o v e r R e m o val
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 -8340 (fig. 13L).
Cam shaft
M easuring Lobe Lift
NOTE: Procedure is similar to that used for
checking valve timing. If improper valve opera­
tion is indicated, measure the lift of each push
rod in consecutive order and record th e
readings.
1. Remove valve mechanism as outlined.
2. Position indicator with ball socket adapter (Tool
J-8520) on push rod (fig. 14L).
3. Rotate the torsional damper 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 damper
slowly, or attach an auxiliary starter switch and
“ bump” the engine over, until the push rod is in the
fully raised position.
C A U TIO N :
The primary distributor lead must
be disconnected from the negative post on the
coil and the ignition switch must be in the on
©
Fig. 13L—Installing O il Seal (Cover Installed)
Fig. 14L—Measuring Camshaft Lobe Lift
CHEVROLET TRUCK SERVICE MANUAL
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