Cam Lobe Lift Measurement - Jeep 1987 Wrangler Workshop Manual

ENGINES
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4.2 LITER (258 CID) SIX-CYLINDER ENGINE
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N O T E : Tap the spring from side-to-side to
ensure that the spring is seated properly on the
cylinder head.
Disconnect the air hose. Remove the adapter
from the spark plug hole and install the spark
plug.
Install the push rods. Ensure the bottom end of
each push rod is centered in the plunger cap
seat of the hydraulic valve tappet.
Install the rocker arms, pivots and bridge at their
original location.
Tighten the bridge capscrews alternately, one
turn at a time, to avoid damaging the bridge.
Install the cylinder head cover. Refer to Cylinder
Head Cover Installation for the procedure.
Cam Lobe Lit Measurement
Remove the cylinder head cover. Refer to
C y l i n d e r H e a d C o v e r R e m o v a l for the
procedure.
Remove the capscrews, bridge and pivot
assemblies, and rocker arms. Alternately loosen
each capscrew, one turn at a time, to avoid
damaging the bridges.
Remove the spark plugs.
Install a dial indicator (1) with a piece of rubber
tubing (2) between the dial indicator plunger and
the push rod (3).
Rotate the crankshaft until the heel of the cam
lobe (push rod in the down position) is under the
valve tappet. Set the dial indicator pointer at
zero.
Rotate the crankshaft until the push rod is at its
maximum upward position. Note the travel
distance on the dial indicator. Refer to the
Specifications chart for the correct cam lobe lift.
Repeat the procedure for each cam lobe.
Valve
Timing
Disconnect the spark plug wires and remove the
spark plugs.
Remove the cylinder head cover Refer to
C y l i n d e r H e a d C o v e r R e m o v a l for the
procedure.