(9) Install the cylinder head cover (Refer to 9 -
ENGINE/CYLINDER
HEAD/CYLINDER
HEAD
COVER(S) - INSTALLATION).
(10) Install upper intake manifold (Refer to 9 -
ENGINE/MANIFOLDS/INTAKE
MANIFOLD
-
INSTALLATION).
(11) Connect negative battery cable.
ROCKER ARM SHAFT /
ROCKER ARM / LASH
ADJUSTER
DESCRIPTION
The two rocker shafts are mounted to the top of
the camshaft bearing caps. The left rocker shaft
holds the eight roller rocker arms for the intake
valves, while the right rocker shaft holds the four
forked roller rocker arms for the exhaust valves. The
roller rocker arms are mounted to rocker shafts and
are positioned over the camshaft and valve stems.
The rocker shaft is installed through the center of
the roller rocker arms, which allows the roller rocker
arms to pivot. The valve stem end of the roller rocker
arms contain a hydraulic lash adjuster. The hydrau-
lic lash adjuster, using oil pressure, constantly main-
tains the correct clearance between the rocker arm
and camshaft/valve stem. The camshaft end of the
roller rocker arm contains a roller that rides on the
lobe of the camshaft. Roller rocker arms provide the
camshaft with a quiet, low-friction means of opening
the valves. Hydraulic lash adjusters are replaced as
an assembly with the rocker arms (Fig. 39).
REMOVAL
(1) Disconnect negative battery cable.
(2) Remove cylinder head cover (Refer to 9 -
ENGINE/CYLINDER
HEAD/CYLINDER
HEAD
COVER - REMOVAL).
NOTE: Use the following procedure to remove both
the intake and exhaust rocker shafts.
CAUTION: To avoid damage to the rocker shafts,
loosen each rocker shaft/camshaft bearing cap bolt
one turn at a time in the following sequence:
(3) Loosen the rocker shaft/camshaft bearing cap
bolts starting with the center bolt and working
toward the ends.
(4) Remove the rocker shafts/roller rocker arm
assemblies (Fig. 39).
NOTE: Hydraulic lash adjusters are replaced as an
assembly with the rocker arms.
INSTALLATION
(1) Lubricate the roller portion of the rocker arms
with clean engine oil.
(2) Install
the
rocker
shaft/roller
rocker
arm
assemblies on the camshaft bearing caps, camshaft,
and valve stems (Fig. 39).
(3) Hand start rocker shaft/camshaft bearing cap
bolts.
NOTE: When tightening the rocker shaft/camshaft
bearing cap bolts, ensure the camshaft bearing
caps are fully seated and the roller rocker arms
remain seated in their proper position.
Fig. 39 Rocker Arm Shafts/Lash Adjusters/Camshaft
1 - EXHAUST VALVE ROCKER ARM
2 - INTAKE VALVE ROCKER ARM SPACER
3 - INTAKE VALVE ROCKER SHAFT
4 - INTAKE VALVE ROCKER ARM
5 - CAMSHAFT
6 - CAMSHAFT BEARING CAP
7 - EXHAUST VALVE ROCKER SHAFT
9 - 36
ENGINE 1.6L SOHC
PT
SPARK PLUG TUBE (Continued)