Dodge ram truck 3500 1996 Service Manual page 1071

BR
5.2L ENGINE 9 - 81
D I S A S S E M B L Y A N D A S S E M B L Y ( C o n t i n u e d )
VALVE SERVICE
VALVE GUIDES
Measure valve stem guide clearance as follows:
(1) Install Valve Guide Sleeve Tool C-3973 over
valve stem and install valve (Fig. 51). The special
sleeve places the valve at the correct height for
checking with a dial indicator.
Reamer O/S Valve Guide Size
0.076 mm
8.026 - 8.052 mm
(0.003 in.) ( 0 . 3 1 6 - 0 . 3 1 7 in.)
0.381 mm
8.331 - 8.357 mm
(0.015 in.) ( 0 . 3 2 8 - 0 . 3 2 9 in.)
J9309-30
Fig. 53 Reamer Sizes
• Step 2—Ream to 0.381 mm (0.015 inch).
REFACING VALVES AND 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. 54).
Fig. 51 Positioning Valve with Tool C-3973
(2) Attach Dial Indicator Tool C-3339 to cylinder
head and set i t at right angle of valve stem being
measured (Fig. 52).
CONTACT
POINT
4574° - 4574°
J9209-91
Fig. 52 Measuring Valve Guide Wear
(3) Move valve to and from the indicator. The total
dial indicator reading should not exceed 0.432 mm
(0.017 inch). Ream the guides for valves with over­
size stems i f dial indicator reading is excessive or i f
the stems are scuffed or scored.
(4) Service valves with oversize stems are avail­
able (Fig. 53).
(5) Slowly turn reamer by hand and clean guide
thoroughly 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 true in relation to the valve
seat:
• Step 1—Ream to 0.0763 mm (0.003 inch).
INTAKE 1.016-1.524 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
0
C - SEAT ANGLE (INTAKE & EXHAUST)
4474°
- 447*°
D - CONTACT SURFACE
J9309-95
Fig. 54 Valve Face and Seat Angles
WALWES
Inspect the remaining margin after the valves are
refaced (Fig. 55). Valves with less than 1.190 mm
(0.047 inch) margin should be discarded.
W A L W E SEATS
CAUTION: DO NOT un-shroud valves during valve
seat refacing (Fig. 56).
(1) When refacing valve seats, it is important that
the correct size valve guide pilot be used for reseat­
ing stones. A true and complete surface must be
obtained.