Chrysler RAM TRUCK 2500 1994 Service Manual page 798

(2) Compress valve springs using Valve Spring
Compressor Tool MD-998772A.
(3) Remove valve retaining locks, valve spring re­
tainers, valve stem seals and valve springs.
(4) Before removing valves, remove any burrs from
valve stem lock grooves to prevent damage to the
valve guides. Identify valves to ensure installation i n
original location.
VALVE CLEANING
Clean valves thoroughly. Discard burned, warped
and cracked valves.
Remove carbon and varnish deposits from inside of
valve guides with a reliable guide cleaner.
VALVE INSPECTION
Measure valve stems for wear. I f wear exceeds
0.051 mm (0.002 inch), replace the valve.
Measure valve stem guide clearance as follows:
(a) Install Valve Guide Sleeve Tool C-3973 over
valve stem and install valve (Fig. 6). The special
sleeve places the valve at the correct height for
checking with a dial indicator.
Fig. 6 Positioning Valve with Tool C-3973
(b) Attach Dial Indicator Tool C-3339 to cylinder
head and set i t at right angle of valve stem being
measured (Fig. 7).
Fig. 7 Measuring Valve Guide Wear
(c) Move valve to and from the indicator. The to­
tal dial indicator reading should not exceed 0.432
mm (0.017 inch). Ream the guides for valves with
oversize stems i f dial indicator reading is excessive
or i f the stems are scuffed or scored.
Service valves with oversize stems are available
(Fig. 8).
Reamer O / S Valve Guide
Size
0.076 mm 8.026 - 8.052 mm
(0.003 in.)
(0.316-0.317in.)
0.381
mm
8.331 - 8.357 mm
(0.015 in.) ( 0 . 3 2 8 - 0 . 3 2 9 in.)
J9309-30
Fig. 8 Reamer Sizes
Slowly turn reamer by hand and clean guide thor­
oughly before installing new valve. Ream the valve
guides from standard to 0.381 mm (0.015 inch).
Use a 2 step procedure so the valve guides are
reamed t r u e i n r e l a t i o n t o the valve seat:
• Step 1-Ream to 0.0763 mm (0.003 inch).
• Step 2-Ream to 0.381 mm (0.015 inch).
REFACING VALVES / VALVE SEATS
The intake and exhaust valves have a 43-1/4° to
43-3/4° face angle and a 44-1/4° to 44-3/4° seat angle
(Fig. 9).
CONTACT
A - SEAT WIDTH - INTAKE 1 . 0 1 6 - 1 . 5 2 4 mm (0.040 - 0.060 in.)
EXHAUST 1.524 - 2.032 mm (0.060 - 0.080 in.)
B - FACE ANGLE (INTAKE & EXHAUST) 4374° - 43 3 A°
C - SEAT ANGLE (INTAKE & EXHAUST) 44 1 A° -
4 4
3 / 4 °
D - CONTACT SURFACE
J9309-95
Fig. 9 Valve Face and Seat Angles