Chevrolet Light Duty Truck 1973, Service Manual

Page: 393 / 979

E N G I N E 6 - 5 7
Fig. 19V—Oil Pan Front Seal Modification
8. Install and partially tighten the two, oil pan-to-front
cover attaching screws.
9. Install the front cover-to-block attaching screws.
10. Torque all screws to specifications.
11. Install torsional damper and water pump as
outlined.
Oil Seal (Front Cover)
Replacement
With Cover Removed
1. With cover removed, pry oil seal out of cover from
the front with a large screw driver.
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 on Small V8 engines or Tool
J-22102 on Mark IV V8 engines (fig. 21V).
CAUTION:
Support cover at seal area. (Tool
J-971 may be used as support).
Fig. 20V—Applying Front Cover Sealer
Fig. 21V—Installing Oil Seal (Cover Removed)
Without Cover Removed
1. With torsional damper removed, pry seal out of
cover from the front with a large screw driver,
being careful not to damage the 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 on Small V8 engines or Tool J-22102
on Mark IV V8 engines (fig. 22V).
Timing Chain and/or Sprockets
Replacement
1. Remove torsional damper and crankcase front
cover as outlined.
2. Crank engine until marks on camshaft and
crankshaft sprockets are in alignment (fig. 23V).
3. Remove camshaft sprocket to camshaft bolts.
4. Remove camshaft sprocket and timing chain
together. Sprocket is a light press fit on camshaft. If
sprocket does not come off easily, a light blow on
the lower edge of the sprocket (with a plastic
mallet) should dislodge the sprocket.
5. If crankshaft sprocket is to be replaced on Small V8
engines remove sprocket using Tool J-5825 (fig.
24V). Install new sprocket using bolt and nut from
J-23523 (fig. 25V). On Mark IV V8 engines remove
sprocket using Tool J-1619 (fig. 26V). Install new
sprocket using bolt and nut from Tool J-23523 (fig.
25V).
6. Install timing chain on camshaft sprocket. Hold the
sprocket vertically with the chain hanging down
and align marks on camshaft and crankshaft
sprockets (fig. 27V).
NOTE: Do not attempt to drive sprocket on
camshaft as welsh plug at rear of engine can
be dislodged.
LIGHT DUTY TRUCK SERVICE MANUAL