Dodge dakota 2002 Service Manual page 1497

9 - 248 ENGINE - 5.9L
INTAKE/EXHAUST VALVES & SEATS (Continued)
ing stones. A true and complete surface must be
obtained.
(2) Measure the concentricity of valve seat using a
dial indicator. Total runout should not exceed 0.051
mm (0.002 in.) total indicator reading.
(3) Inspect the valve seat with Prussian blue, to
determine where the valve contacts the seat. To do
this, coat valve seat LIGHTLY with Prussian blue
then set valve in place. Rotate the valve with light
pressure. If the blue is transferred to the center of
valve face, contact is satisfactory. If the blue is trans-
ferred to the top edge of valve face, lower valve seat
with a 15° stone. If the blue is transferred to bottom
edge of valve face raise valve seat with a 60° stone.
(4) When seat is properly positioned the width of
intake seats should be 1.016-1.524 mm (0.040-0.060
in.). The width of the exhaust seats should be 1.524-
2.032 mm (0.060-0.080 in.).
VALVE SPRINGS
Whenever valves have been removed for inspection,
reconditioning or replacement, valve springs should
be tested. As an example the compression length of
the spring to be tested is 1-5/16 in.. Turn table of
Universal Valve Spring Tester Tool until surface is in
line with the 1-5/16 in. mark on the threaded stud.
Be sure the zero mark is to the front (Fig. 15). Place
spring over stud on the table and lift compressing
lever to set tone device. Pull on torque wrench until
ping is heard. Take reading on torque wrench at this
instant. Multiply this reading by 2. This will give the
spring load at test length. Fractional measurements
are indicated on the table for finer adjustments.
Refer to specifications to obtain specified height and
allowable tensions. Discard the springs that do not
meet specifications.
Fig. 15 Testing Valve Spring for Compressed
1 - TORQUE WRENCH
2 - VALVE SPRING TESTER
Length
REMOVAL
(1) Remove the cylinder head (Refer to 9 -
ENGINE/CYLINDER HEAD - REMOVAL).
(2) Compress valve springs using Valve Spring
Compressor Tool MD- 998772A and adapter 6716A.
(3) Remove valve retaining locks, valve spring
retainers, 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 in
original location.
CLEANING
Clean valves thoroughly. Discard burned, warped,
or cracked valves.
Remove carbon and varnish deposits from inside of
valve guides with a reliable guide cleaner.
INSPECTION
Measure valve stems for wear. If wear exceeds
0.051 mm (0.002 in.), replace the valve.
Measure valve stem guide clearance as follows:
(1) Install Valve Guide Sleeve Tool C-3973 over
valve stem and install valve (Fig. 16). The special
sleeve places the valve at the correct height for
checking with a dial indicator.
Fig. 16 Positioning Valve with Tool C-3973
1 - VALVE
2 - SPACER TOOL
(2) Attach dial indicator Tool C-3339 to cylinder
head and set it at right angles to valve stem being
measured (Fig. 17).
(3) Move valve to and from the indicator. The total
dial indicator reading should not exceed 0.432 mm
(0.017 in.). Ream the guides for valves with oversize
stems if dial indicator reading is excessive or if the
stems are scuffed or scored.
INSTALLATION
(1) Clean valves
warped and cracked valves.
(2) Remove carbon and varnish deposits from
inside of valve guides with a reliable guide cleaner.
thoroughly. Discard
DR
burned,