1998 DODGE RAM 1500 air

(5) Rotate the compressor nut counter-clockwise to
relieve tension on the springs. Remove the spring
compressor.
(6) Remove the retainers, springs, valve seals (if
necessary), and valves (Fig. 24). Arrange or number
all components so they can be installed in their orig-
inal locations.
(7) Repeat the procedure on all cylinders to be ser-
viced.
CLEANING
Clean the valve stems with crocus cloth or a
Scotch-BriteŸ pad. Remove carbon with a soft wire
brush. Clean valves, springs, retainers, and valve
retaining locks in a suitable solvent. Rinse in hot
water and blow dry with compressed air.
INSPECTION
Visually inspect the valves for abnormal wear on
the heads, stems, and tips. Replace any valve that is
worn out or bent (Fig. 25).
Measure the valve stem diameter in three places
as shown in (Fig. 26).
Measure the cylinder head valve guide bore (Fig.
27).
VALVE GUIDE BORE SPECIFICATIONS
VALVE GUIDE BORE SPECIFICATIONS
Valve guide bore
diameter
Min. 7.027 mm (0.2767 in.)
Max. 7.077 mm (0.2786 in.)
Installed valve guide
depth
Intake
Min. 0.584 mm ( 0.023 in.)
Max. 1.092 mm ( 0.043 in.)
Exhaust
Min. 0.965 mm ( 0.028 in.)
Max. 1.473 mm (0.058 in.)
Fig. 24 Valve Spring, Seal, and Retainers
1 - VALVE RETAINING LOCKS
2 - VALVE
3 - SEAL
4 - SPRING
5 - RETAINER
Fig. 25 Visually Inspect Valves for Abnormal Wear
Fig. 26 Measure Valve Stem Diameter
VALVE STEM DIAMETER
6.96 mm (0.2740 in.) MIN
7.010 mm (0.2760 in.) MAX
DRENGINE 5.9L DIESEL 9 - 257
INTAKE/EXHAUST VALVES & SEATS (Continued)

INSTALLATION
(1) Install new valve seals. The yellow seals are for
the intake valves and the green seals are for the
exhaust valves.
(2) Install the valves in their original postion. The
exhaust valves are identified by a dimple on the
valve head (Fig. 31).
(3) Install the valve springs and retainer.
(4) Install the valve spring compressor tool 8319±A
as shown in (Fig. 22) and (Fig. 23).
(5) Compress the valve springs and install the
valve retaining locks (Fig. 24).
(6) Remove the compressor and repeat the proce-
dure on the remaining cylinders.
(7) Install new o-ring and sealing washer on injec-
tor.
(8) Lubricate o-ring and injector bore.
(9) Verify sealing washer (shim) was removed with
old injector.
(10) Install injector Refer to (Refer to 14 - FUEL
SYSTEM/FUEL INJECTION/FUEL INJECTOR -
INSTALLATION).
(11) Install the cylinder head (Refer to 9 -
ENGINE/CYLINDER HEAD - INSTALLATION).
STANDARD PROCEDURE - VALVE LASH
ADJUSTMENT AND VERIFICATION
NOTE: To obtain accurate readings, valve lash mea-
surements AND adjustments should only be per-
formed when the engine coolant temperature is less
than 60É C (140É F).
The 24±valve overhead system is a ªlow-mainte-
nanceº design. Routine adjustments are no longer
necessary, however, measurement should still takeplace when trouble-shooting performance problems,
or upon completion of a repair that includes removal
and installation of the valve train components or
injectors.
(1) Disconnect battery negative cables.
(2) Remove cylinder head cover (Refer to 9 -
ENGINE/CYLINDER HEAD/CYLINDER HEAD
COVER(S) - REMOVAL).
(3) Using the crankshaft barring tool #7471±B,
rotate crankshaft to align damper TDC mark to
12:00 o'clock position.
(a) If both number one cylinder rocker levers are
loose, continue to next step.
(b) If both number one clylinder rocker levers
are not loose, rotate crankshaft 360 degrees.
(4) With the engine in this position, valve lash can
be measured at the following rocker arms:INTAKE
1±2±4 / EXHAUST 1±3±5. Measure the valve lash by
inserting a feeler gauge between the rocker arm
socket and crosshead (Fig. 32). Refer to VALVE
LASH LIMIT CHART for the correct specifications. If
the measurement fallswithinthe limits, adjust-
ment/resettingis notnecessary. If measurement
finds the lashoutsideof the limits, adjustment/re-
settingisrequired.
VALVE LASH LIMIT CHART
INTAKE EXHAUST
0.152 mm ( 0.006 in.)
MIN.0.381 mm (0.015 in.)
MIN.
0.381 mm (0.015 in.)
MAX.0.762 mm (0.030 in.)
MAX.
note:
If measured valve lash falls within these
specifications, no adjustment/reset is necessary.
Engine operation within these ranges has no adverse
affect on performance, emissions, fuel economy or
level of engine noise.
(5) If adjustment/resetting is required, loosen the
lock nut on rocker arms and turn the adjusting screw
until the desired lash is obtained:
²INTAKE0.254 mm (0.010 in.)
²EXHAUST0.508 mm (0.020 in.) Tighten the
lock nut to 24 Nm (18 ft. lbs.) and re-check the valve
lash.
(6) Using the crankshaft barring tool, rotate the
crankshaftone revolution (360É) to align the
damper TDC mark to the 12 o'clock position.
Fig. 31 Valve Identification
1 - INTAKE VALVES
2 - EXHAUST VALVES
DRENGINE 5.9L DIESEL 9 - 259
INTAKE/EXHAUST VALVES & SEATS (Continued)

(7) With the engine in this position, valve lash can
be measured at the remaining rocker arms:INTAKE
3±5±6 / EXHAUST 2±4±6. Use the same method as
above for determining whether adjustment is neces-
sary, and adjust those that are found to be outside of
the limits.
(8) Install the cylinder head cover (Refer to 9 -
ENGINE/CYLINDER HEAD/CYLINDER HEAD
COVER(S) - INSTALLATION).
(9) Connect the battery negative cables.
REMOVAL - VALVE SPRINGS AND SEALS
(1) Disconnect the battery negative cables.
(2) Remove the cylinder head cover (Refer to 9 -
ENGINE/CYLINDER HEAD/CYLINDER HEAD
COVER(S) - REMOVAL).
(3) Disconnect rocker housing injector harness con-
nector. Remove all injector harness solenoid nuts.
(4) Remove injector(s) for cylinder(s) to be serviced.
Refer to Group 14 for injector removal.
(5) Remove the rocker housing.
(6) Remove the rocker arms and crossheads from
the cylinder(s) to be serviced. Mark each component
so they can be installed in their original position.
(7) Using the crankshaft barring tool #7471±B
(Fig. 33), rotate the engine to position the damper
mark in the 12 o'clock position.At this engine posi-
tion, cylinders #1 and #6 can be serviced.
(8) Remove the accessory drive belt (Refer to 7 -
COOLING/ACCESSORY DRIVE/DRIVE BELTS -
REMOVAL).
(9) With the damper TDC mark in the 12 o'clock
position, add a paint mark anywhere on the gear
housing cover next to the crankshaft damper. Place
another mark on the vibration damper in alignment
with the mark you just made on the cover.(10) Divide the crankshaft damper into three
equally sized segments as follows:
(a) Using a tape measure, measure the circum-
ference of the crankshaft damper and divide the
measurement by three (3).
(b) Measure that distance in a counter-clockwise
direction from the first balancer mark and place
another mark on the balancer.
(c) From the second damper mark, again mea-
sure in a counter-clockwise direction and place a
mark on the damper at the same distance you
measured when placing the second damper mark.
The damper should now be marked in three
equally spaced locations and the damper TDC
mark should be in the 12 o'clock position.
(d) Remove injectors, fuel lines, and high pres-
sure connectors for every cylinder that requires
repair.
(11) Compress the valve springs at cyls. #1 and #6
as follows:
(a) Install the valve spring compressor mounting
base as shown in (Fig. 34).
(b) Install the top plate, washer, and nut. Using
a suitable wrench tighten the nut (clock-wise) (Fig.
35) to compress the valve springs and remove the
collets.
(c) Rotate the compressor nut counter-clockwise
to relieve tension on springs. Remove spring com-
pressor.
(d) Remove and replace retainers, springs, and
seals as necessary.
(e)Do not rotate the engine until the
springs and retainers are re-installed.
(f) Install seals, springs and retainers. Install
spring compressor, compress valve springs and
install the collets.
Fig. 32 Measuring Valve Lash - Typical
1 - INTAKE
2 - FEELER GAUGE
3 - EXHAUST
Fig. 33 Rotating Engine with Barring Tool - Typical
1 - REAR FLANGE
2 - BARRING TOOL
9 - 260 ENGINE 5.9L DIESELDR
INTAKE/EXHAUST VALVES & SEATS (Continued)

NOTE: The #5 cyl. intake and exhaust and #6 cyl.
intake and exhaust push rods must be raised
through the provided cowl panel access holes.
(5) Lift the crosshead(s) off of the valve stems.
Mark them so they can be installed in their original
position.
CLEANING
Clean all components in a suitable solvent. If nec-
essary, use a wire brush or wheel to remove stubborn
deposits. Rinse in hot water and blow dry with com-
pressed air. Inspect oil passages in rocker arms and
pedestals. Apply compressed air to lubrication orifices
to purge contaminants.
INSPECTION
Rocker Arms
(1) Remove rocker shaft and inspect for cracks and
excessive wear in the bore or shaft. Remove socket
and inspect ball insert and socket for signs of wear.
Replace retainer if necessary.
Measure the rocker arm bore and shaft (Fig. 39)
(Fig. 40).
Fig. 36 Rocker Arm and Pedestal Removal
1 - ROCKER ARM
2 - PEDESTAL
Fig. 37 Rocker Arm Assembly Identification
1 - NUT
2 - ADJUSTING SCREW
3 - ROCKER SHAFT
4 - RETAINER
5 - SOCKET
Fig. 38 Push Rod Removal/Installation
Fig. 39 Measuring Rocker Arm Bore
ROCKER ARM BORE (MAX.)
22.027 mm (.867 in.)
9 - 262 ENGINE 5.9L DIESELDR
ROCKER ARM / ADJUSTER ASSY (Continued)

(6) Use a drill, a fine grit Flex-hone and a mixture
of equal parts of mineral spirits and SAE 30W engine
oil to de-glaze the bores.
(7) The crosshatch angle is a function of drill
speed and how fast the hone is moved vertically (Fig.
47).
(8) Vertical strokes MUST be smooth continuous
passes along the full length of the bore (Fig. 47).
(9) Inspect the bore after 10 strokes.
(10) Use a strong solution of hot water and laun-
dry detergent to clean the bores. Clean the cylinder
bores immediately after de-glazing.
(11) Rinse the bores until the detergent is removed
and blow the block dry with compressed air.
(12) Check the bore cleanliness by wiping with a
white, lint free, lightly oiled cloth. If grit residue is
still present, repeat the cleaning process until all res-
idue is removed. Wash the bores and the complete
block assembly with solvent and dry with compressed
air. Place a clean shop towel around the top main
bearing saddle to deflect water and residue from pis-
ton cooling nozzels. Remove directed piston cooling
nozzles if installed.
(13) Be sure to remove the tape covering the lube
holes, rod journals, and piston cooling nozzles after
the cleaning process is complete.
STANDARD PROCEDUREÐCYLINDER BORE
REPAIR
Cylinder bore(s) can be repaired by one of two
methods:
²Method 1:ÐOver boring and using oversize pis-
tons and rings.
²Method 2:ÐBoring and installing a repair sleeve
to return the bore to standard dimensions.
METHOD 1ÐOVERSIZE BORE
Cylinder bore(s) can be repaired by one of two
methods:Oversize pistons and rings are available in two
sizes - 0.50 mm (0.0197 inch) and 1.00 mm (0.0393
inch).
Any combination of standard, 0.50 mm (0.0197
inch) or 1.00 mm (0.0393 inch) overbore may be used
in the same engine.
If more than 1.00 mm (0.0393 inch) overbore is
needed, a repair sleeve can be installed (refer to
Method 2ÐRepair Sleeve).
Cylinder block bores may be bored twice before use
of a repair sleeve is required. The first bore is 0.50
mm (0.0197 inch) oversize. The second bore is 1.00
mm (0.0393 inch) oversize.
After boring to size, use a honing stone to chamfer
the edge of the bore.
CYLINDER BORE DIMENSION CHART
DESCRIPTION MEASUREMENT
BORING DIAMETER
DIMENSION1st. REBORE - 102.469
mm (4.0342 in.)
2nd. REBORE - 102.969
mm (4.0539 in.)
HONING DIAMETER
DIMENSIONSSTANDARD - 102.020  
0.020 mm (4.0165  
0.0008 in.)
1st. REBORE - 102.520
  0.020 mm (4.0362  
0.0008 in.)
2nd. REBORE - 103.020
  0.020 mm 4.0559  
0.0008 in.)
CHAMFER
DIMENSIONSApprox. 1.25 mm (0.049
in.) by 30É
A correctly honed surface will have a crosshatch
appearance with the lines at 15É to 25É angles with
the top of the cylinder block (Fig. 48). For the rough
hone, use 80 grit honing stones. To finish hone, use
280 grit honing stones.
A maximum of 1.2 micrometer (48 microinch) sur-
face finish must be obtained.
Fig. 47 De-Glazing Drill Speed and Vertical Speed
Fig. 48 Crosshatch Pattern of Repaired Sleeve(s)
DRENGINE 5.9L DIESEL 9 - 265
ENGINE BLOCK (Continued)

After finish honing is complete, immediately clean
the cylinder bores with a strong solution of laundry
detergent and hot water.
After rinsing, blow the block dry.
Check the bore cleanliness by wiping with a white,
lint-free, lightly- oiled cloth. There should be no grit
residue present.
If the block is not to be used right away, coat it
with a rust- preventing compound.
METHOD 2ÐREPAIR SLEEVE
If more than a 1.00 mm (0.03937 inch) diameter
oversize bore is required, the block must be bored
and a repair sleeve installed.
Bore the block cylinder bore to 104.500-104.515
mm (4.1142-4.1148 inch) - (Fig. 49).
Repair sleeves can be replaced by using a boring
bar to bore out the old sleeve. DO NOT cut the cyl-
inder bore beyond the oversize limit.
REPAIR SLEEVE BLOCK REBORE
DIMENSIONS CHART
BORE DIAMETER STEP DIMENSION
104.500 + 0.015 mm
(4.1142 + 0.0006 in.)6.35 mm (0.25 in.)
After machining the block for the new repair
sleeve, thoroughly clean the bore of all metal chips,
debris and oil residue before installing the sleeve.
Cool the repair sleeve(s) to a temperature of -12ÉC
(10ÉF) or below for a minimum of one hour. Be ready
to install the sleeve immediately after removing it
from the freezer.
Apply a coat of Loctite 620, or equivalent to the
bore that is to be sleeved.Wear protective gloves to push the cold sleeve into
the bore as far as possible.
Using a sleeve driver, drive the sleeve downward
until it contacts the step at the bottom of the bore
(Fig. 50).
A sleeve driver can be constructed as follows (Fig.
51).SLEEVE DRIVER CONSTRUCTION
SPECIFICATION CHART
ITEM MEASUREMENT
A 127 mm (5 in.)
B 38 mm (1.5 in.)
C 6.35 mm (0.25 in.)
D 25.4 mm (1 in.)
E 101 mm (3.976 in.)
F 107.343 mm (4.226 in.)
Set up a boring bar and machine the sleeve to
101.956 mm (4.014 inch).
Fig. 49 Block Bore for Repair Sleeve Dimensions
1 - BORE DIAMETER
2 - STEP DIMENSION
Fig. 50 Sleeve Installation
1 - SLEEVE DRIVER
2 - SLEEVE
3 - CONTACT
Fig. 51 Sleeve Driver Construction
1 - DRIVE
2 - HANDLE
9 - 266 ENGINE 5.9L DIESELDR
ENGINE BLOCK (Continued)

After removing the boring bar, use a honing stone
to chamfer the corner of the repair sleeve(s).
SLEEVE MACHINING DIMENSIONS CHART
ITEM MEASUREMENT
SLEEVE PROTRUSION MIN. - FLUSH WITH
BLOCK
MAX. - 0.050 mm
(0.0019 in.)
SLEEVE DIAMETER 101.956 mm (4.014 in.)
SLEEVE CHAMFER APPROX. 1.25 mm
(0.049 in.) by 15É
A correctly honed surface will have a crosshatch
appearance with the lines at 15É to 25É angles with
the top of the cylinder block. For the rough hone, use
80 grit honing stones. To finish hone, use 280 grit
honing stones.
Finished bore inside dimension is 102.020  0.020
mm (4.0165  0.0008 inch).
A maximum of 1.2 micrometer (48 microinch) sur-
face finish must be obtained.
After finish honing is complete, immediately clean
the cylinder bores with a strong solution of laundry
detergent and hot water.
After rinsing, blow the block dry with compressed
air.
Wipe the bore with a white, lint-free, lightly oiled
cloth. Make sure there is no grit residue present.
Apply a rust-preventing compound if the block will
not be used immediately.
A standard diameter piston and a piston ring set
must be used with a sleeved cylinder bore.
STANDARD PROCEDUREÐCAM BORE REPAIR
For standard bushings, not oversized, maximum
front and rear cam bushing bore diameter is 59.248
mm. (2.3326 in.). DO NOT bore the intermediate cam
bore to the front cam bore oversize dimensions. Max-
imum front and rear camshaft bushing installed
diameter is 54.147 mm. (2.1318 in.). Minimum
installed diameter is 54.083 mm. (2.1293 in.). Maxi-
mum intermediate camshaft bore diameter is 54.164
mm. (2.1324 in.).
A surface finish of 2.3 micrometers (92 microinch)
must be maintained. Not more than 20% of an area
of any one bore may be 3.2 micrometers (126 micro-
inch).
Camshaft bores can be repaired individually. It is
not necessary to repair undamaged cam bores in
order to repair individually damaged cam bores. The
standard front bushing cannot be used to repair
intermediate bores.Install all cam bushings flush or below the front
and rear cam bore surface. The front camshaft bush-
ing should be installed flush with front face of block.
The rear camshaft bushing should be installed flush
with rear face of block. The oil hole must align to
allow a 3.2 mm (0.125 inch) rod to pass through
freely (Fig. 52).
INSPECTION
Measure the combustion deck face using a straight
edge and a feeler gauge (Fig. 53). Cylinder block flat-
ness: End-to-end 0.076 mm ( .003 in.). Maximum
variation side-to-side 0.051 mm (.002 in.).
Inspect for any localized dips or imperfections.
If the surface exceeds the limit, (Refer to 9 -
ENGINE/ENGINE BLOCK - STANDARD PROCE-
DURE).
Fig. 52 Oil Hole Alignment
1 - CAMSHAFT BUSHING
Fig. 53 Combustion Deck Face Measurement
1 - STRAIGHT EDGE
2 - FEELER GAUGE
DRENGINE 5.9L DIESEL 9 - 267
ENGINE BLOCK (Continued)

Inspect the cylinder bores for damage or excessive
wear.
Measure the cylinder bores (Fig. 54). If the cylin-
der bores exceed the limit, (Refer to 9 - ENGINE/EN-
GINE BLOCK - STANDARD PROCEDURE).
BORE SPECIFICATIONS
BORE DIAMETER
Min. 102.000 mm (4.0157 in.)
Max. 102.116 mm (4.0203 in.)
OUT OF ROUNDNESS
Max. 0.038 mm (0.0015 in.)
TAPER
Max. 0.076 mm (.003 in.)
Inspect the camshaft bores for scoring or excessive
wear.
Measure the camshaft bores (Refer to 9 - ENGINE
- SPECIFICATIONS).
If a bore exceeds the limit, (Refer to 9 - ENGINE/
ENGINE BLOCK/CAMSHAFT & BEARINGS (IN
BLOCK) - STANDARD PROCEDURE).
Inspect the tappet bores for scoring or excessive
wear.
Measure tappet bore from bottom of block. Mini-
mum tappet bore diameter 16.000 mm (0.0630 in.).
Maximum tappet bore 16.055 mm. (0.632 in.).
If out of limits, replace the cylinder block.
CAMSHAFT & BEARINGS (IN
BLOCK)
REMOVAL
REMOVALÐCAMSHAFT BEARINGS
NOTE: Measure the diameter of each bore. If the
camshaft bore for the first or rear cam bushing is
worn beyond the limit, install a new service bush-
ing. Inspect the rest of the camshaft bores for dam-
age or excessive wear.If the bores without a
bushing are worn beyond the limit, the engine must
be removed for machining and installation of ser-
vice bushings. If badly worn, replace the cylinder
block.
(1) Remove the camshaft (Refer to 9 - ENGINE/
ENGINE BLOCK/CAMSHAFT & BEARINGS (IN
BLOCK) - REMOVAL).
(2) Remove the bushing from the No.1 bore and
No.7 using a universal cam bushing tool.
(3) Mark the cylinder block so you can align the oil
hole in the cylinder block with the oil hole in the
bushing.
REMOVAL - CAMSHAFT
(1) Disconnect both battery negative cables.
(2) Recover A/C refrigerant (if A/C equipped) (Refer
to 24 - HEATING & AIR CONDITIONING/PLUMB-
ING - STANDARD PROCEDURE).
(3) Raise vehicle on hoist.
(4) Drain engine coolant into container suitable for
re-use (Refer to 7 - COOLING - STANDARD PROCE-
DURE).
(5) Lower vehicle.
(6) Remove radiator upper hose.
(7) Remove viscous fan/drive assembly and fan
shroud (Refer to 7 - COOLING/ENGINE/RADIATOR
FAN - REMOVAL).
(8) Disconnect the coolant recovery bottle hose
from the radiator filler neck.
(9) Disconnect lower radiator hose from radiator
outlet.
(10)Automatic Transmission models:Discon-
nect transmission oil cooler lines from front of radia-
tor using Special Tool 6931 (unless equipped with
finger-release disconnect).
(11) Remove radiator mounting screws and lift
radiator out of engine compartment.
(12) Remove upper radiator support panel.
(13) If A/C equipped, disconnect A/C condenser
refrigerant lines.
(14) Disconnect charge air cooler piping from the
cooler inlet and outlet.
Fig. 54 Cylinder Bore Diameter
9 - 268 ENGINE 5.9L DIESELDR
ENGINE BLOCK (Continued)