Timing Chain And Gears - GMC 1976 ZEO 6083 Maintenance Manual

6A- 52
ENGINE
3. Apply lubricant 1050169 or equivalent, on pul-
ley hub seal surface.
4. Install oil pan. See "Oil Pan" earlier in this
section.
5 . Install harmonic balancer and crankshaft pul-
ley. Refer to "Harmonic Balancer" and "Crankshaft
Pulley" earlier in this section.
6 . Install belts. Refer to "Belt Tension" earlier in
this section.
lbs.
7. Install venturi ring and torque nuts to 20 ft .
8. Install fan clutch assembly and torque nuts to
15 ft . lbs.
9. Roll shroud-to-venturi ring seal off of shroud
and install shroud seal retainer strap.
10 . Connect radiator hoses, heater hoses and by-
pass hose to water pump and radiator .
11 . Replace oil drain plug and shut radiator drain
cock .
12 . Lower vehicle.
13 . Fill radiator and crankcase . Start engine and
check for leaks.
TIMING CHAIN AND GEARS
REMOVAL
1 . Raise vehicle.
2. Remove front cover. See "Front Cover" earlier
in this section .
Figure 58-Crankshaft Gear Removal
3. Remove fuel pump eccentric.
4. Remove oil slinger, camshaft and timing chain.
5. Remove key then crankshaft gear .
NOTE : Gear to crankshaft fit tolerances may be
such that a puller is necessary. (See figure 58).
CAUTION :
Remove crankshaft key, ifpossi-
ble before usingpulley; ifnot, align puller so
that it does not overlap end of key when
using puller, keyway is machined only part
way in crankshaft gear and breakage would
occur.
INSTALLATION
1 . Install camshaft gear crankshaft gear and tim-
ing chain together, and then align timing marks as
shown in Figure 59 .
NOTE : When the timing marks are in alignment
(Figure 59), number six is at T.D .C . To obtain
T.D .C . for number one cylinder, slowly rotate
crankshaft one rotation, this will bring the cam
mark to the top, number one will then be in the
firing position .
2 . Install fuel pump eccentric with flat side rear-
ward . See Figure 60 . Torque bolt to 65 ft . lbs .
Figure 59-Timing Gear Position