Dodge RAM TRUCK 1500 1995 Service Manual page 934

S - I I S J L E i i i i E
i n
The tappet should be replaced. A heavy click is
caused by a tappet check valve not seating or by for­
eign particles becoming wedged between the plunger
and the tappet body. This will cause the plunger to
stick in the down position. This heavy click will be
accompanied by excessive clearance between the
valve stem and rocker arm as valve closes, in either
case, tappet assembly should be removed for inspec­
tion and cleaning.
The valve train generates a noise very much like a
light tappet noise during normal operation. Care
must be taken to ensure that tappets are making the
noise. In general, if more than one tappet seems to
be noisy, its probably not the tappets.
REMOVAL
(1) Remove the air cleaner.
(2) Remove cylinder head cover.
(3) Remove rocker assembly and push rods. Iden­
tify push rods to ensure installation in original loca­
tion.
(4) Remove intake manifold.
(5) Remove yoke retainer and aligning yokes.
(6) Slide Hydraulic Tappet Remover/Installer Tool
C-4129-A through opening in cylinder head and seat
tool firmly in the head of tappet.
(7) Pull tappet out of bore with a twisting motion.
If all tappets are to be removed, identify tappets to
ensure installation in original location,
(8) If the tappet or bore in cylinder block is scored,
scuffed, or shows signs of sticking, ream the bore to
next oversize. Replace with oversize tappet.
CAUTION: The plunger and tappet bodies are not
interchangeable. The plunger and valve must al­
ways- be fitted to the original body. It is advisable to
work on one tappet at a time to avoid mixing of
parts.'Mixed parts are not compatible. DO NOT dis­
assemble a tappet on a dirty work bench,
DISASSEMBLE
(1) Pry out plunger retainer spring clip (Fig. 12).
(2) Clean varnish deposits from inside of tappet
body above plunger cap.
(8) Invert tappet body and remove plunger cap,
plunger, check valve, check valve spring, check valve
retainer and plunger spring (Fig. 12). Check valve
could be flat or ball.
ASSEMBLE
(1) Clean all tappet parts in a solvent that will re­
move all varnish and carbon.
(2) Replace tappets that are unfit for further ser­
vice with new assemblies.
(3) If plunger shows signs of scoring or wear, in­
stall a new tappet assembly. If valve is pitted, or
valve seat on end of plunger is prevented from seat­
ing, install a new tappet assembly,
(4) Assemble tappets (Fig, 12).
SPRING CAP J9109-220
Fig. 12 Hydraulic Tappet Assembly
INSTALLATION
(1) Lubricate tappets,
(2) Install tappets and push rods in their original
positions. Ensure that the oil feed hole in the side of
the tappet body faces up (away from the crankshaft).
(3) Install rocker arm and shaft assembly.
(4) install vent cover.
(5) Install distributor, start engine and reset tim­
ing.
CAUTION; To prevent damage to valve mechanism,
engine must not be run above fast idle until all hy­
draulic tappets have filled with oil and have become
quiet.
VALVE TIMING
(1) Turn crankshaft until the No.6 exhaust valve is
closing and No.6 intake valve is opening.
(2) Insert a 6.350 mm (1/4 inch) spacer between
rocker arm pad and stem tip of No.l intake valve. Al­
low spring load to bleed tappet down giving in effect
a solid tappet.
(3) Install a dial indicator so plunger contacts
valve spring retainer as nearly perpendicular as pos­
sible. Zero the indicator.
(4) Rotate the crankshaft clockwise (normal run­
ning direction) until the valve has lifted 0.863 mm
(0.034 inch). The timing of the crankshaft should
now read from 10° before top dead center to 2° after
top dead center. Remove spacer. .
CAUTION; D O NOT turn crankshaft any further
clockwise as valve spring might bottom and result
in serious damage.
(5) If reading is not within specified limits:
(a) Check sprocket index marks.
(b) Inspect timing chain for wear.
(c) Check accuracy of DC mark on timing indica­
tor.