CONDITION POSSIBLE CAUSES CORRECTION
2. Engine running too cold. 2. Refer to Coolant Temperature Below
Normal (Refer to 7 - COOLING -
DIAGNOSIS AND TESTING).
3. Oil viscosity too thick. 3. Make sure the correct oil is being used.
(Refer to LUBRICATION &
MAINTENANCE/FLUID TYPES -
DESCRIPTION).
4. Oil pressure relief valve stuck
closed or binding4. Check and replace valve.
LUBRICATING OIL LOSS 1. External leaks. 1. Visually inspect for oil leaks. Repair as
required.
2. Crankcase being overfilled. 2. Verify that the correct dipstick is being
used.
3. Incorrect oil specification or
viscosity.3. (a) Make sure the correct oil is being
used (Refer to LUBRICATION &
MAINTENANCE/FLUID TYPES -
DESCRIPTION).
(b) Look for reduced viscosity from dilution
with fuel.
(c) Review/reduce oil change intervals.
4. Oil cooler leak 4. Check and replace the oil cooler.
5. High blow-by forcing oil out the
breather.5. Check the breather tube area for signs of
oil loss. Perform the required repairs.
6. Turbocharger leaking oil to the air
intake.6. Inspect the air ducts for evidence of oil
transfer. Repair as required.
COMPRESSION KNOCKS 1. Air in the fuel system. 1. Identify location of air leak and repair. Do
not bleed high pressure fuel system.
2. Poor quality fuel or water/gasoline
contaminated fuel.2. Verify by operating from a temporary
tank with good fuel. Clean and flush the
fuel tank. Replace fuel/water separator filter.
3. Engine overloaded. 3. Verify the engine load rating is not being
exceeded.
4. Improperly operating injectors. 5. Check and replace misfiring/inoperative
injectors.
EXCESSIVE VIBRATION 1. Loose or broken engine mounts. 1. Replace engine mounts.
2. Damaged fan or improperly
operating accessories.2. Check and replace the vibrating
components.
3. Improperly operating vibration
damper3. Inspect/replace vibration damper.
4. Improperly operating electronically
controlled viscous fan drive.4. Inspect/replace fan drive.
5. Worn or damaged generator
bearing.5. Check/replace generator.
6. Flywheel housing misaligned. 6. Check/correct flywheel alignment.
9 - 234 ENGINE 5.9L DIESELDR
ENGINE 5.9L DIESEL (Continued)
(10) Drain engine oil. Remove and discard the oil
filter (Refer to 9 - ENGINE/LUBRICATION/OIL FIL-
TER - REMOVAL).
(11) Install the drain plug. Tighten the plug to 50
N´m (37 ft. lbs.) torque.
(12) Install a new oil filter (Refer to 9 - ENGINE/
LUBRICATION/OIL FILTER - INSTALLATION).
(13) Fill engine crankcase with the specified
amount and grade of oil (Refer to LUBRICATION &
MAINTENANCE/FLUID TYPES - SPECIFICA-
TIONS).
(14) Connect the negative cable(s) to the battery.
(15) Start the engine and check for any leaks.
REMOVAL
REMOVAL - ENGINE
(1) Disconnect both battery negative cables.
(2) Disconnect engine grid heater harness at grid
heater relays.
(3) Disconnect electrical connections from rear of
alternator.
(4) Recover A/C refrigerant. (Refer to 24 - HEAT-
ING & AIR CONDITIONING/PLUMBING - STAN-
DARD PROCEDURE).
(5) Raise vehicle on a hoist.
(6) Drain engine coolant (Refer to 7 - COOLING -
STANDARD PROCEDURE).
(7) Remove engine oil drain plug and drain engine
oil.
(8) Reinstall drain plug. Tighten to 50N´m (37 ft.
lbs.) torque.
(9) Lower the vehicle.
(10) Remove fan/drive assembly. Refer to Section 7
± Fan/Drive Removal
(11) Remove radiator upper hose.
(12) Remove upper fan shroud mounting bolts.
(13) Disconnect the coolant recovery bottle hose
from the radiator fill neck and remove bottle.
(14) Using a 36mm wrench, remove viscous fan/
drive assembly. (Refer to 7 - COOLING/ENGINE/RA-
DIATOR FAN - REMOVAL).
(15) Remove cooling fan and shroud together.
(16) Disconnect heater core supply and return
hoses from the cylinder head fitting and coolant pipe.
(17) Raise vehicle on a hoist.
(18) Remove transmission and transfer case (if
equipped).
(19) Disconnect exhaust pipe from turbocharger
extension pipe.
(20) Disconnect engine harness to vehicle harness
connectors.
(21) Remove starter motor (Refer to 8 - ELECTRI-
CAL/STARTING/STARTER MOTOR - REMOVAL).(22) Remove flywheel/flexplate.
(23) Remove transmission adapter
(24) Disconnect A/C suction/discharge hose from
the rear of the A/C compressor.
(25) Lower vehicle.
(26) Disconnect lower radiator hose from radiator
outlet.
(27) Automatic transmission models:
(28) Disconnect transmission oil cooler lines from
in front of radiator using special tool #6931
(29) Remove radiator. (Refer to 7 - COOLING/EN-
GINE/RADIATOR - REMOVAL).
(30) If A/C equipped, disconnect A/C condenser
refrigerant lines.
(31) Disconnect charge air cooler piping.
(32) Remove charge air cooler mounting bolts.
(33) Remove charge air cooler (and A/C condenser
if equipped) from vehicle.
(34) Remove damper and speed indicator ring from
front of engine.
(35) Disconnect engine block heater connector.
(36) Disconnect A/C compressor and pressure sen-
sor electrical connectors.
(37) Remove the passenger battery ground cable
from the engine block. Remove the driver side bat-
tery ground cable from the engine block.
(38) Remove power steering pump from engine by
removing 3 bolts.
(39) Remove accelerator linkage cover.
(40) Disconnect cables from on-engine APPS.
(41) Disconnect the ECM power connector.
(42) Disconnect the ECM ground wire from the
hydroform screw.
(43) Disconnect the fuel supply and return hoses.
(44) Remove the cylinder head cover. (Refer to 9 -
ENGINE/CYLINDER HEAD/CYLINDER HEAD
COVER(S) - REMOVAL).
(45) Disconnect the 3 injector harness connectors
at the rocker housing. Disconnect the wire harnesses
from the injectors.
(46) Remove the rear engine lift bracket.
(47) Remove cylinder #4, #5, and #6 intake and
exhaust rocker arms, pedestals, and push tubes. Note
the original location for re-assembly.
(48) Loosen #6 fuel line shield bolts and rotate
shield out of the way.
(49) Remove cylinder #5 and #6 high pressure fuel
lines. Remove the fuel connector tube nut and fuel
connector tube. Remove cylinder #5 and #6 fuel injec-
tor.
(50) Remove rocker housing.
DRENGINE 5.9L DIESEL 9 - 241
ENGINE 5.9L DIESEL (Continued)
LUBRICATION
DESCRIPTION
NOTE: Refer to (Fig. 105) and (Fig. 106) for circuit
illustrations.
A gear driven gerotor type oil pump is mounted
behind the front gear cover in the lower right portion
on the engine.
OPERATION
A gerotor style oil pump draws oil from the crank-
case through the suction tube and delivers it through
the block where it enters the oil cooler cover and
pressure regulator valve. When oil pressure exceeds
517 kPa (75 PSI), the valve opens exposing the dump
port, which routes excess oil back to the oil pump.
At the same time, oil is directed to a cast in pas-
sage in the oil cooler cover, leading to the oil cooler
element. As the oil travels through the element
plates, it is cooled by engine coolant traveling past
the outside of the plates. It is then routed to the oil
filter head and through a full flow oil filter. If a
plugged filter is encountered, the filter by-pass valve
opens, allowing unfiltered oil to lubricate the engine.
This condition can be avoided by frequent oil and fil-
ter changes, per the maintenance schedules found in
the owners manual. The by-pass valve is calibrated
to open when it sees a pressure drop of more than
345 kPa (50 psi) across the oil filter.
The oil filter head then divides the oil between the
engine and the turbocharger. The turbocharger
receives filtered, cooled and pressurized oil through a
supply line from the filter head. The oil lubricates
the turbocharger and returns to the pan by way of a
drain tube connecting the bottom of the turbocharger
to a pressed in tube in the cylinder block.
Oil is then carried across the block to an angle
drilling which intersects the main oil rifle. The main
oil rifle runs the length of the block and delivers oil
to the crankshaft main journals and valve train. Oil
travels to the crankshaft through a series of transfer
drillings (one for each main bearing) and lubricates a
groove in the main bearing upper shell. From there
another drilling feeds the camshaft main journals.The saddle jet piston cooling nozzles are also sup-
plied by the main bearing upper shell. J-jet piston
cooling nozzles are supplied by a separate oil rifle.
Plugs are used in place of saddle jets when J-jets are
used. J-jet hole locations are plugged when saddle jet
cooling nozzles are used. Crankshaft internal cross-
drillings supply oil to the connecting rod journals.
Another series of transfer drillings intersecting the
main oil rifle supply the valve train components. Oil
travels up the drilling, through a hole in the head
gasket, and through a drilling in the cylinder head
(one per cylinder), where it enters the rocker arm
pedestal and is divided between the intake and
exhaust rocker arm. Oil travels up and around the
rocker arm mounting bolt, and lubricates the rocker
shaft by cross drillings that intersect the mounting
bolt hole. Grooves at both ends of the rocker shaft
supply oil through the rocker arm where the oil trav-
els to the push rod and socket balls (Fig. 105) and
(Fig. 106).
DIAGNOSIS AND TESTINGÐENGINE OIL
PRESSURE
(1) Remove the 1/8 npt plug from the top of the oil
filter housing.
(2) Install Oil Pressure Line and Gauge Tool
C-3292 with a suitable adapter.
(3) Start engine and warm to operating tempera-
ture.
(4) Record engine oil pressure and compare with
engine oil pressure chart.
CAUTION: If engine oil pressure is zero at idle, DO
NOT RUN THE ENGINE.
Engine Oil Pressure (MIN)
At Idle 68.9 kPa (10 psi)
At 2500 rpm 206.9 kPa (30 psi)
If minimum engine oil pressure is below these
ranges, (Refer to 9 - ENGINE - DIAGNOSIS AND
TESTING).
(5) Remove oil pressure gauge and install the 1/8
npt plug.
DRENGINE 5.9L DIESEL 9 - 289
OIL
STANDARD PROCEDURE
STANDARD PROCEDURE - ENGINE OIL LEVEL
CAUTION: Do not overfill crankcase with engine oil,
oil foaming and oil pressure loss can result.
To ensure proper lubrication of an engine, the
engine oil must be maintained at an acceptable level.
The acceptable oil level is in the SAFE RANGE on
the engine oil dipstick (Fig. 107).
(1) Position vehicle on level surface.
(2) With engine OFF, allow approximately 15 min-
utes for oil to settle to bottom of crankcase, remove
engine oil dipstick.
(3) Wipe dipstick clean.
(4) Replace dipstick and verify it is seated in the
tube.
(5) Remove dipstick, with handle held above the
tip, take oil level reading.
(6) Add oil only if level is below the SAFE RANGE
area on the dipstick.
(7) Replace dipstick
STANDARD PROCEDURE - ENGINE OIL
SERVICE
WARNING: HOT OIL CAN CAUSE PERSONAL
INJURY.
NOTE: Change engine oil and filter at intervals
specified in the owner's manual.
(1) Operate the engine until the water tempera-
ture reaches 60ÉC (140ÉF). Shut the engine off.
(2) Use a container that can hold at least 14 liters
(15 quarts) to hold the used oil. Remove the oil drain
plug and drain the used engine oil into the container.
(3) Always check the condition of the used oil. This
can give you an indication of engine problems that
might exist.
²Thin, black oil indicates fuel dilution.
²Milky discoloration indicates coolant dilution.
(4) Clean the area around the oil filter head.
Remove the filter (Refer to 9 - ENGINE/LUBRICA-
TION/OIL FILTER - REMOVAL).
(5) Install new oil filter (Refer to 9 - ENGINE/LU-
BRICATION/OIL FILTER - INSTALLATION).
(6) Clean the drain plug and the sealing surface of
the pan. Check the condition of the threads and seal-
ing surface on the oil pan and drain plug.
(7) Install the drain plug. Tighten the plug to 50
N´m (37 ft. lbs.) torque.
(8) Use only High-Quality Multi-Viscosity lubricat-
ing oil in the Cummins Turbo Diesel engine. Choose
the correct oil for the operating conditions (Refer to
LUBRICATION & MAINTENANCE/FLUID TYPES -
DESCRIPTION).
(9) Fill the engine with the correct grade of new oil
(Refer to LUBRICATION & MAINTENANCE/FLUID
CAPACITIES - SPECIFICATIONS).
(10) Start the engine and operate it at idle for sev-
eral minutes. Check for leaks at the filter and drain
plug.
(11) Stop engine. Wait 15 minutes to allow the oil
to drain back to the pan and check the level again.
USED ENGINE OIL DISPOSAL
Care should be exercised when disposing of used
engine oil after it has been drained from a vehicle's
engine.
1 - ROCKER ARM
2 - ROCKER SHAFT
3 - PEDESTAL
4 - FROM MAIN OIL RIFLE
5 - TO VALVE TRAIN
6 - MAIN OIL RIFLE
7 - FROM MAIN OIL RIFLE8 - TO CAMSHAFT
9 - TO PISTON COOLING NOZZLE
10 - FROM OIL COOLER
11 - CRANKSHAFT MAIN JOURNAL
12 - ROD JOURNAL
13 - TO ROD BEARING
14 - MAIN OIL RIFLE
Fig. 107 Oil Level Indicator (Dipstick)
1 - ADD OIL MARK
2 - O-RING
3 - SAFE RANGE
9 - 292 ENGINE 5.9L DIESELDR
LUBRICATION (Continued)
SPORT FASCIA REMOVAL
(1) Raise and support the vehicle. (Refer to
LUBRICATION & MAINTENANCE/HOISTING -
STANDARD PROCEDURE)
(2) Remove the three screws at each trailing edge
of the fascia. (Fig. 3)
(3) Remove the five lower screws.
(4) Remove and discard the four upper push pins.
(5) Using a trim stick C-4755 or equivalent, care-
fully release the six lower clips and remove the close
out panel.
(6) Using a trim stick C-4755 or equivalent, care-
fully remove the step pad.
(7) Spread the fascia out at the wheels and remove
from the vehicle.
INSTALLATION
NOTE: The left and right inboard bumper to bracket
attachments must be secured before installing the
fascia and step pad.
ST/SLT/SLT+ FASCIA INSTALLATION
(1) Install the fascia.
(2) Position the close out panel and seat the 6
lower clips fully.
(3) Install four new upper push pin fasteners.
(4) Position the step pad onto the fascia and fully
seat the attachment clips.(5) Align the fascia to the fender with a 19 mm
(0.75 inch) gap and install the two screws at each
trailing edge of the fascia.
SPORT FASCIA INSTALLATION
(1) Position the fascia onto the bumper.
(2) Position the step pad onto the fascia and fully
seat the attachment clips.
(3) Install four new upper push pin fasteners.
(4) Install the five lower screws.
(5) Install the three screws at each trailing edge of
the fascia.
REAR BUMPER
REMOVAL
(1) Raise and support the vehicle. (Refer to
LUBRICATION & MAINTENANCE/HOISTING -
STANDARD PROCEDURE)
(2) Remove the license plate.
(3) Remove the bolts behind the plate.
(4) Disconnect the license plate light electrical con-
nectors.
(5) Disconnect the trailer light connector electrical
connection, if equipped.
(6) Remove the two bolts along the front upper
edge of the bumper near the frame tips.
(7) Support the bumper with a suitable lifting
device.
(8) Remove the bolts attaching the bumper support
brackets to the trailer hitch. (Fig. 4)
Fig. 3 SPORT FASCIA
1 - STEP PAD
2 - FASCIA (SPORT MODEL ONLY)
3 - SCREWS (3 PER SIDE)
4 - UPPER FASCIA SUPPORT BRACKET
5 - WHEELHOUSE SPLASH SHIELD BRACKET
6 - INBOARD BUMPER BRACKET ATTACHMENTS
7 - PUSH PIN FASTENERS (4)
8 - LOWER SCREWS (5)
Fig. 4 TRAILER HITCH
1 - HITCH
2 - LD HITCH BOLTS (4)/HD (6)
3 - BUMPER BRACKET BOLTS (4)
4 - BUMPER SUPPORT BRACKETS
DRFRAMES & BUMPERS 13 - 3
FRONT FASCIA (Continued)
SPECIFICATIONS - TORQUE
TORQUE SPECIFICATIONS
DESCRIPTION N´m Ft. Lbs. In. Lbs.
Cab mount bolts 81 60 Ð
Cargo box bolts 108 80 Ð
Front crossmember bolts - 2WD (light duty only) 61 45 Ð
Front crossmember bolts - 2WD (heavy duty only) 75 55 Ð
Front crossmember bolts - 4WD (light duty only) 102 75 Ð
Front skid plate bolts 34 25 Ð
Lower bumper support bracket bolt 54 40 Ð
Radiator crossmember bolts - lower 28 21 Ð
Radiator crossmember bolts - upper 28 21 Ð
Rear crossmember (light duty only) 102 75 Ð
Rear crossmember (heavy duty only) 115 85 Ð
Rear spring shackle bolts 163 120 Ð
Spare tire winch bolts 41 30 Ð
Trailer hitch reinforcement bracket bolt 170 125 Ð
Transfercase skid plate bolts 34 25 Ð
Transercase skid plate crossmember bolts 34 25 Ð
Transmission mount to crossmember nuts 54 40 Ð
FRONT CROSSMEMBER
REMOVAL
(1) Raise and support the vehicle. (Refer to
LUBRICATION & MAINTENANCE/HOISTING -
STANDARD PROCEDURE)
(2) Remove the front skid plate, if equipped. (Refer
to 13 - FRAME & BUMPERS/FRAME/FRONT SKID
PLATE - REMOVAL)
(3) Remove the bolts and remove the crossmember.
(Fig. 28) or (Fig. 29)
INSTALLATION
(1) Install the crossmember.
(2) Install the bolts;
²On light duty 2WD vehicles, tighten the bolts to
61 N´m (45 ft. lbs.).
²On light duty 4WD vehicles, tighten the bolts to
102 N´m (75 ft. lbs.).
²On heavy duty 2WD vehicles, tighten the bolts
to 75 N´m (55 ft. lbs.).
(3) Install the front skid plate, if equipped. (Refer
to 13 - FRAME & BUMPERS/FRAME/FRONT SKID
PLATE - INSTALLATION)
Fig. 28 FRONT CROSSMEMBER - 2WD
1 - CROSSMEMBER
2 - BOLTS (2 PER SIDE)
13 - 22 FRAMES & BUMPERSDR
FRAME (Continued)
FRONT SKID PLATE
REMOVAL
(1) Raise and support the vehicle. (Refer to
LUBRICATION & MAINTENANCE/HOISTING -
STANDARD PROCEDURE)
(2) Remove the bolts. (Fig. 30)
(3) Slide skid plate back off of the crossmember
and remove.
INSTALLATION
(1) Snap the rear tabs over the front crossmember
and install the skid plate.
(2) Install the bolts and tighten to 34 N´m (25 ft.
lbs.).
FRONT TOW HOOK ASSEMBLY
REMOVAL
(1) Remove front bumper. (Refer to 13 - FRAME &
BUMPERS/BUMPERS/FRONT BUMPER -
REMOVAL)
(2) Remove the bolts and remove the tow hook
assembly. (Fig. 31) and (Fig. 32)
INSTALLATION
(1) Install the tow hook assembly and bolts hand
tight.
(2) Install the front bumper. (Refer to 13 - FRAME
& BUMPERS/BUMPERS/FRONT BUMPER -
INSTALLATION)
(3) Tighten the tow hook bolts to 68 N´m (50 ft.
lbs.).
Fig. 29 FRONT CROSSMEMBER - 4WD
1 - BOLTS (2 PER SIDE)
2 - CROSSMEMBER
Fig. 30 FRONT SKID PLATE
1 - FRONT CROSSMEMBER
2 - FRONT SKID PLATE
3 - BOLTS (2)
Fig. 31 FRONT TOW HOOK ASSEMBLY
1 - BUMPER CENTER SUPPORT BRACKET
2 - BOLTS (6)
3 - TOW HOOK ASSEMBLY
DRFRAMES & BUMPERS 13 - 23
FRONT CROSSMEMBER (Continued)
TRANSMISSION
CROSSMEMBER
REMOVAL
(1) Raise and support the vehicle. (Refer to
LUBRICATION & MAINTENANCE/HOISTING -
STANDARD PROCEDURE)
(2) Remove the transfercase skid plate, if
equipped. (Refer to 13 - FRAME & BUMPERS/
FRAME/TRANSFER CASE SKID PLATE -
REMOVAL)
(3) Support the transmission with a suitable lifting
device.
(4) Remove the transmission mount nuts. (Fig. 33)
or (Fig. 34)
(5) Remove the bolts and remove the crossmember.
INSTALLATION
(1) Install the crossmember and install the bolts.
²On light duty vehicles, tighten the bolts to 102
N´m (75 ft. lbs.).
²On heavy duty vehicles, tighten the bolts to 115
N´m (85 ft. lbs.).
(2) Install the transmission mount nuts and
tighten to 54 N´m (40 ft. lbs.).(3) Remove the transmission support.
(4) Install the transfercase skid plate. (Refer to 13
- FRAME & BUMPERS/FRAME/TRANSFER CASE
SKID PLATE - INSTALLATION)
Fig. 32 FRONT TOW HOOK ASSEMBLY ± HEAVY
DUTY
1 - BOLTS (4 PER HOOK)
2 - HEAVY DUTY TOW HOOKS (2)
3 - BUMPER CENTER SUPPORT BRACKETS
Fig. 33 REAR CROSSMEMBER - 2WD
1 - TRANSMISSION MOUNT
2 - REAR CROSSMEMBER
3 - TRANSMISSION MOUNT NUTS (2)
4 - CROSSMEMBER BOLTS (2 PER SIDE)
Fig. 34 REAR CROSSMEMBER - 4WD
1 - TRANSMISSION MOUNT
2 - TORSION BAR
3 - CROSSMEMBER BOLTS (3 PER SIDE)
4 - REAR CROSSMEMBER
5 - TRANSMISSION MOUNT NUTS (2)
13 - 24 FRAMES & BUMPERSDR
FRONT TOW HOOK ASSEMBLY (Continued)