Chrysler RAM TRUCK 2500 1994 Service Manual page 852

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5JL (DIESEL) ENGINE 9 - 131
Polish the valve stems with crocus cloth.
Inspect for abnormal wear on the valve heads and
stems. Replace badly worn valves.
Check for bent valves. Replace bent valves.
Measure the valve stem diameter (Fig. 2). The
valve stem diameter should be 7.935-7.960 mm
(0.3126-0.3134 inch). I f out of limits, replace the
valve. Mark the new valves with the replacement lo­
cation.
VALVE RIM
THICKNESS
J !
J
MEASURE AT THESE POINTS
J9109-144
Fig. 2 Measure Valve Stem Diameter
Inspect the end of the valve stem for flatness.
I f required, resurface the valve end.
WALWE GRINDING
The valve seat angle should be 30° (Intake Valve)
and 45° (Exhaust Valve) - (Fig. 3). .
INTAKE
E X H A U S T
J 9 1 0 9 - 4 1
0
0
O r / 0 0 (
00° 0c
O
Fig. 3 Valve Seat Angle
Measure the r i m thickness (Fig. 4). The minimum
valve r i m thickness is 0.79 mm (0.031 inch).
Grind the face of valves to be reused.
Check the valve stem tip for flatness. I f required,
re-surface the tip.
WALWE GUIDES
INSPECTION
Inspect the valve guides for scuffing or scoring.
Measure the valve guide bore (Fig. 5). The bore di­
ameter should be 8.019-8.089 mm (0.3157-0.3185
inch).
J9109-146
Fig. 4 Valve Rim Thickness
N E W DIAMETER LIMITS
8.019-8.029 mm (0.3157-0.3165 inch)
W O R N LIMIT
8.090 mm (0.3185 inch)
J9109-135
Fig. 5 Valve Guide Bore
I f the valve guide bores are larger than the worn
limit, the cylinder head must be machined for service
valve guides. New valve guides must be reamed to
size after they are installed.
I f the cylinder head needs service valve guides and
valve seat inserts, the valve guides should be in­
stalled first.
INSTALLATION
T H I N WALL-SERVICE GUIDES
Machine the cylinder head valve guide bores to
11.125 ±0.013 mm (0.4380 ±0.0005 inch) i n diameter
(Fig. 6).
Service valve guides must be centered with valve
seats within 0.35 mm (0.01378 inch) diameter. They
must also be square with the combustion face within
0.10 mm (0.004 inch) at 50.0 mm (1.9685 inch) ra­
dius.
Lubricate the valve guides with oil and press the
guides flush to the bottom of the bosses.