Valve Train Com Ponent In Stallatio; Valve Adjustment; Intake Manifold In Stallatio; Rocker Arm Cover In S Ta Lla Tio - Chevrolet 1988 Light Duty Truck Repair Manual

4 i FRONT
Figure 38— Cylinder Head Bolt Tightening Sequence
VALVE TRAIN COMPONENT
INSTALLATION
Im p o rta n t
Replace all hydraulic lifters if a new cam shaft was
installed.
|-n~| Install o r C on n ect (F ig u re 39)
• Lubricate the hydraulic lifter bodies and feet with
Engine Oil Supplem ent (GM Part NO. 1051396 or
equivalent).
1. Hydraulic lifters to the block.
2. Restrictors (46) and retainer (41) with bolts (40).
T ig h te n
• Bolts (40) to 16.4 N m (145 in. lbs.).
3. Pushrods.
• S eat the pushrods into the socket in the
hydraulic lifters.
• Coat the mating surfaces of the rocker arms and
balls with " Molykote" or equivalent.
4. Rocker arms.
5. Balls.
6. Nuts.

VALVE ADJUSTMENT

1. Crank the engine until the mark on the torsional
dam per lines up with the " O " mark on the tim ing
tab and the e n g ine in the n u m b e r one firin g
position. This may be determ ined by placing fingers
on the num ber one valve as the mark on the dam per
com es near the " O " mark on the tim ing tab. If the
rocker arms are not moving, the engine is in the
num ber one firing position. If the rocker arms move
as the mark comes up to the tim ing tab, the engine
is in the number four firing position and should be
turned over one more time to reach the num ber one
position.
2. W ith the engine in the number one firing position as
determ ined above, the follow ing valves may be
adjusted:
— Exhaust: 1, 5, 6.
— Intake; 1, 2, 3.
(Even numbered cylinders are in the right bank; odd
num bered cylinders are in the left bank, when
viewed from the rear of the engine).
3. Back out the adjusting nut until lash is felt at the
pushrod then turn in the adjusting nut until all lash
is removed. This can be determ ined by rotating the
pushrod while turning the adjusting nut. When the
play has been removed, turn the adjusting nut in
one full additional turn (to center the lifter plunger).
4. Crank the engine one revolution until the tim ing tab
" O " mark and torsional dam per mark are again in
alignm ent. This is the num ber four firing position.
The following valves may be adjusted:
B-07874
— Exhaust: 2, 3, 4.
— Intake: 4, 5, 6.
Install or C o n n ec t (F ig u res 40 and 41)
1. Gaskets to the cylinder head with the port blocking
plates facing the rear of the engine.
2. RTV to the front and rear sealing surfaces on the
block. Apply a 5 mm (3/ie-inch) bead of RTV (GM
Part No. 1052366 or equivalent) to the front and rear
of the block as shown in figure 40. Extend the bead
13 mm (1 /
retain the gaskets.
3. Intake manifold to the engine.
4. Intake m anifold bolts.
$ T ig h te n
B o lts to 48 N m (35 ft. lb s .) u s in g
tightening sequence shown in figure 41.
ROCKER ARM COVER
E
Install or C o n n ec t (F ig u re 42)
1. Rocker arm cover and new gasket.
2. Rocker arm cover bolts and washers.
• Rocker arm cover bolts to 10.2 N-m (90 in.
lbs.).
EXHAUST MANIFOLD
+«-
Install or C o n n e c t (F ig u re 43)
1. Exhaust manifold.
2. Heat shield (if removed).
3. Exhaust manifold bolts, washers, and tab washers.
$
T ig h ten
Bolts on center exhaust tube to 36 N m (26 ft.
lbs.).
4.3 LITER V-6 6A3-23
INTAKE MANIFOLD
INSTALLATION
2 -inch) up each cylinder head to seal and
INSTALLATION
INSTALLATION
th e