GMC 4000 Series Service Manual page 289

______________________ G M C S E R V I C E M A N U A L
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GASOLINE ENGINES
Thrust
B e a rin g
________
Figure 3 6 — Tool Application for Crankshaft
Pulley or Hub Installation
INSTALLATION
1. Clean seal area on crankshaft pulley or hub
thoroughly and apply engine oil on surface contact­
ed by oil seal.
2. Align key way in pulley or hub with key in
crankshaft, then start pulley or hub onto front end
of crankshaft. Assem ble special installer shown in
figure 36, and turn nut with wrench to force pulley
firmly into place on crankshaft.
3. Remove installer, then referring to figure
37, locate cone (when used) at hub, and install re­
taining washer and bolt. Tighten retaining bolt with
torque wrench to 95 to 105 foot-pounds torque on
engines without cone-type retainer. If cone is used
the correct torque is 180 to 200 foot-pounds.
Figure 3 7 — Crankshaft Pulley Retaining
Parts (Engine with Cone Retainer Sh ow n )
^ Pu lley i
In sta lle rl
1 Pulley Installer
2 Oil Seal Install­
er
3 Key
CRANKSHAFT FRONT COVER OIL
REMOVAL
1. Remove crankshaft pulley or hub as previ­
ously instructed under "Crankshaft Pulley Re­
placement."
2. Use suitable tool to pry oil seal out of front
cover.
INSTALLATION
A special Tool (J-7879-01) is available for
installing crankshaft front oil seal assembly with­
out removing front cover.
1. Lubricate oil seal lip with engine oil, then
turn engine crankshaft so key (3, fig. 38) is at top
as shown.
2. Locate new seal assembly at bore in front
cover with seal lip pointing inward, then assem ble
special tool components in manner shown in fig­
ure 38.
3. Tighten nut against thrust bearing to force
seal squarely into cover bore.
4. Inspect surface on pulley hub, with mag­
nifying glass if necessary, to locate any nicks,
burrs, or scratches which could cause rapid wear
at oil seal. When inspection shows surface to be in
poor condition, install a new pulley or hub.
5. Install crankshaft pulley or hub following
instructions previously given under "Crankshaft
Pulley Replacement."
OIL PAN REMOVAL
1. Clean all dirt and accumulated material
Engine Front
Cover
Crankshaft Gear
or Sprocket
Oil Slinger
Oil Seal Assy.
Crankshaft
Installer Screw
Installer Nut
Thrust Bearing
( J - 7 8 7 9 - 1 0 )
Figure 3 8 — Front Cover O il Seal Installation
(with Cover Installed on Engine)
SEAL REPLACEMENT
OIL PAN REPLACEMENT