GMC 4000 Series Service Manual page 308

1 Manifold Clamp
2 Intake Manifold
3 Oil Level Dipstick
4 Clamp Bolt_______
2. Remove cover-to-cylinder head screw s,
then lift off covers and gaskets.
NOTE: Do not pry on cover flanges if gasket
is stuck, since prying will bend cover flanges.
Strike cover with rubber mallet if necessary to
loosen stuck covers.
INSTALLATION
1. P ress new cover gaskets into place at
cover flanges.
2. Locate covers at cylinder heads and install
attaching screw s.
VALVE OPERATING M ECHANISM
REPLACEMENT
REMOVAL
1. Remove rocker arm covers referring to
instructions given previously.
2. Remove bolts which hold rocker arm brac­
kets to cylinder heads, then remove rocker arm
shaft and bracket assem blies.
3. Remove push rods and identify so they may
be reinstalled in original locations.
G M C S E R V I C E M A N U A L
5 Cylinder Head
6 Manifold End Bolt
7 Plain Washer and Lock
Washer________
Figure 8 — M anifolds Installed (Right H and Side)
INSTALLATION
then referring to figure 9, bolt rocker arm shaft
brackets in place, meanwhile being careful to en­
gage rocker arm screw s with sockets in push rods.
Tighten bracket bolts 20 to 25 foot-pounds torque.
end brackets and adjacent rocker arm. If a clear­
ance of approximately 0.030-inch does not exist,
loosen bracket bolts, and relocate brackets as al­
lowed by clearance in bracket holes, then tighten
bolts to specified torque.
ance of 0.012-inch at intake valves, and 0.022-inch
at exhaust valves.
are initial "cold" settings. Final adjustment must
be made with engine warmed up to normal operat­
ing temperature. Correct valve lash with engine
warmed up and running is 0.010-inch at intake
valves and 0.018-inch at exhaust valves.
to instructions given previously.
TORO-FLOW DIESEL ENGINE
8 Exhaust Manifold
9 Tube Clamp and Bracket
10 Dipstick Tube
1. Place all push rods in original locations,
2. Check clearance between rocker arm shaft
3. Make initial adjustment to provide clear­
NOTE: The foregoing valve clearances (lash)
4. Install valve rocker arm covers, referring
Sec. 6B
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