Chevrolet 70 Series 1970, Service Manual

Page: 385 / 841

GASOLINE ENGINES 6A-14
rem oved. The sp e c ia l tool typically illu stra ted in
figu re 13 m ust be u sed to sta rt the pulley retaining
cone off crankshaft.
REMOVAL
1. R em ove radiator if n e c e ssa r y , to provide
a c c e s s to crankshaft p u lley . On engines with fai*
blad es in sta lled on crankshaft p u lley, rem ove fan
blad es from crankshaft pulley hub. A lso rem ove
a c c e s s o r y d rive b e lts.
2. U se im pact w rench, or hold engine flyw heel
and u se conventional w rench to rem ove p ulley r e ­
taining bolt.
3. A ssem b le p u lle r and center plug in manner
shown in figu re 13, then turn p u ller sc r e w to re­
m ove p u lley or hub from crankshaft.
INSTALLATION
1. Clean s e a l area on crankshaft pulley or
hub thoroughly and apply engine o il on su rface
contacted by o il s e a l. Seal m ust r o ll into damper
hub counterbore as dam per i s in stalled .
2. A lign keyway in pulley with key in crank­
shaft, then sta r t p ulley or hub onto front end of
crankshaft. A ssem b le sp e c ia l in sta lle r shown in
figu re 14, and turn nut with wrench to fo r c e pulley
firm ly into p la ce on crankshaft.
3. R em ove in sta lle r , then referrin g to figure
15, lo ca te cone at hub on 478M en gin es. Install
retaining w asher and bolt. When phosphate coated
bolt is used, tighten bolt to 180-200 foot-pounds
torque. If cadm ium plated bolt i s used , co r r e ct
torque i s 240 to 260 foot-pounds.
CRANKSHAFT FRONT OIL SEAL
REPLACEMENT
REMOVAL
1. R em ove crankshaft pulley or hub a s p r e ­
v io u sly instructed under "Crankshaft P u lley and
Hub R eplacem ent."
2. U se su itab le tool to pry o il s e a l out of front
co v e r.
1 S eal "O " Ring
2 S lin g er
3 Key
4 In s ta lle r
5 I n s ta lle r Screw
6
T h ru s t Bearing
7 C ra n k sh a ft D am p er
8
C ran k sh aft
9 Engine F ro n t C over
10 O il S eal T
-2172
Figure 14—Installing Damper Assembly on
Crankshaft with Special Tool Set
INSTALLATION
A sp e c ia l tool (J-7879-10) i s availab le for in­
sta llin g crankshaft front o il se a l a ssem b ly without
rem oving front co v er.
1. Lubricate o il s e a l lip with engine o il, then
turn engine crankshaft so key (3, fig. 14) i s at top
a s shown.
2. L ocate new s e a l a ssem b ly at bore in front
co v e r with s e a l lip pointing inward, then a ssem b le
s p e c ia l to o l com ponents as shown in figure 16.
3. Tighten nut against thrust bearing to fo rce
s e a l squarely into cover b ore.
4. Inspect su rfa ce on pulley hub, with m agni­
fying g la ss if n e c e ssa r y , to lo ca te any n ick s, burrs,
or scr a tc h e s which could cau se rapid w ear at o il
Figure 13—Crankshaft Pulley Removal (Typical)
b o l t ^ B J L e t a ,n e r ' t 1
132
§
Figure 15—Crankshaft Hub Retaining Ports (Typical)
CHEVROLET SERIES 70-90 HEAVY DUTY TRUCK SHOP MANUAL