2001 DODGE RAM heating

Condition Possible Causes Correction
Axle Overheating 1. Lubricant level low. 1. Fill differential to correct level.
2. Improper grade of lubricant. 2. Fill differential with the correct fluid
type and quantity.
3. Bearing pre-loads too high. 3. Re-adjust bearing pre-loads.
4. Insufficient ring gear backlash. 4. Re-adjust ring gear backlash.
Gear Teeth Broke 1. Overloading. 1. Replace gears. Examine other gears
and bearings for possible damage.
2. Erratic clutch operation. 2. Replace gears and examine the
remaining parts for damage. Avoid
erratic clutch operation.
3. Ice-spotted pavement. 3. Replace gears and examine
remaining parts for damage.
4. Improper adjustments. 4. Replace gears and examine
remaining parts for damage. Ensure ring
gear backlash is correct.
Axle Noise 1. Insufficient lubricant. 1. Fill differential with the correct fluid
type and quantity.
2. Improper ring gear and pinion
adjustment.2. Check ring gear and pinion contact
pattern. Adjust backlash or pinion depth.
3. Unmatched ring gear and pinion. 3. Replace gears with a matched ring
gear and pinion.
4. Worn teeth on ring gear and/or
pinion.4. Replace ring gear and pinion.
5. Loose pinion bearings. 5. Adjust pinion bearing pre-load.
6. Loose differential bearings. 6. Adjust differential bearing pre-load.
7. Mis-aligned or sprung ring gear. 7. Measure ring gear run-out. Replace
components as necessary.
8. Loose differential bearing cap bolts. 8. Inspect differential components and
replace as necessary. Ensure that the
bearing caps are torqued tot he proper
specification.
9. Housing not machined properly. 9. Replace housing.
REMOVAL
(1) Raise and support the vehicle.
(2) Position a suitable lifting device under the
axle.
(3) Secure axle to device.
(4) Remove the wheels and tires.
(5) Secure brake drums to the axle shaft.
(6) Remove the RWAL sensor from the differential
housing, if necessary. Refer to 5 Brakes for proce-
dures.
(7) Disconnect the brake hose at the axle junction
block. Do not disconnect the brake hydraulic lines at
the wheel cylinders. Refer to 5 Brakes for procedures.(8) Disconnect the parking brake cables and cable
brackets.
(9) Disconnect the vent hose from the axle shaft
tube.
(10) Mark the propeller shaft and companion
flange for installation alignment reference.
(11) Remove propeller shaft.
(12) Disconnect shock absorbers from axle.
(13) Remove the spring clamps and spring brack-
ets. Refer to 2 Suspension for procedures.
(14) Separate the axle from the vehicle.
BR/BEREAR AXLE - 286RBI 3 - 173
REAR AXLE - 286RBI (Continued)

(3) During road test, make normal and firm brake
stops in 25-40 mph range. Note faulty brake opera-
tion such as low pedal, hard pedal, fade, pedal pulsa-
tion, pull, grab, drag, noise, etc.
(4) Attempt to stop the vehicle with the parking
brake only and note grab, drag, noise, etc.
PEDAL FALLS AWAY
A brake pedal that falls away under steady foot
pressure is generally the result of a system leak. The
leak point could be at a brake line, fitting, hose, or
caliper/wheel cylinder. If leakage is severe, fluid will
be evident at or around the leaking component.
Internal leakage (seal by-pass) in the master cylin-
der caused by worn or damaged piston cups, may
also be the problem cause.
An internal leak in the ABS or RWAL system may
also be the problem with no physical evidence.
LOW PEDAL
If a low pedal is experienced, pump the pedal sev-
eral times. If the pedal comes back up, worn linings,
rotors, drums, or rear brakes out of adjustment are
the most likely causes. The proper course of action is
to inspect and replace all worn component and make
the proper adjustments.
SPONGY PEDAL
A spongy pedal is most often caused by air in the
system. However, thin brake drums or substandard
brake lines and hoses can also cause a spongy pedal.
The proper course of action is to bleed the system,
and replace thin drums and substandard quality
brake hoses if suspected.
HARD PEDAL OR HIGH PEDAL EFFORT
A hard pedal or high pedal effort may be due to
lining that is water soaked, contaminated, glazed, or
badly worn. The power booster or check valve could
also be faulty.
PEDAL PULSATION
Pedal pulsation is caused by components that are
loose, or beyond tolerance limits.
The primary cause of pulsation are disc brake
rotors with excessive lateral runout or thickness vari-
ation, or out of round brake drums. Other causes are
loose wheel bearings or calipers and worn or dam-
aged tires.
NOTE: Some pedal pulsation may be felt during
ABS/EBD activation.BRAKE DRAG
Brake drag occurs when the lining is in constant
contact with the rotor or drum. Drag can occur at one
wheel, all wheels, fronts only, or rears only.
Drag is a product of incomplete brake shoe release.
Drag can be minor or severe enough to overheat the
linings, rotors and drums.
Minor drag will usually cause slight surface char-
ring of the lining. It can also generate hard spots in
rotors and drums from the overheat-cool down pro-
cess. In most cases, the rotors, drums, wheels and
tires are quite warm to the touch after the vehicle is
stopped.
Severe drag can char the brake lining all the way
through. It can also distort and score rotors and
drums to the point of replacement. The wheels, tires
and brake components will be extremely hot. In
severe cases, the lining may generate smoke as it
chars from overheating.
Common causes of brake drag are:
²Seized or improperly adjusted parking brake
cables
²Loose/worn wheel bearing
²Seized caliper or wheel cylinder piston
²Caliper binding on damaged or missing anti-rat-
tle clips or bushings
²Loose caliper mounting
²Drum brake shoes binding on worn/damaged
support plates
²Mis-assembled components
²Long booster output rod
If brake drag occurs at all wheels, the problem
may be related to a blocked master cylinder return
port, or faulty power booster (binds-does not release).
BRAKE FADE
Brake fade is usually a product of overheating
caused by brake drag. However, brake overheating
and resulting fade can also be caused by riding the
brake pedal, making repeated high deceleration stops
in a short time span, or constant braking on steep
mountain roads. Refer to the Brake Drag information
in this section for causes.
BRAKE PULL
Front brake pull condition could result from:
²Contaminated lining in one caliper
²Seized caliper piston
²Binding caliper
²Loose caliper
²Damaged anti-rattle clips
²Improper brake shoes
²Damaged rotor
A worn, damaged wheel bearing or suspension
component are further causes of pull. A damaged
5 - 6 BRAKESBR/BE
HYDRAULIC/MECHANICAL (Continued)

Discard the brake springs and retainer components
if worn, distorted or collapsed. Also replace the
springs if a brake drag condition had occurred. Over-
heating will distort and weaken the springs.
Inspect the brake shoe contact pads on the support
plate, replace the support plate if any of the pads are
worn or rusted through. Also replace the plate if it is
bent or distorted (Fig. 60).
ADJUSTMENT - REAR BRAKE DRUM
The rear drum brakes are equipped with a self-ad-
justing mechanism. Under normal circumstances, the
only time adjustment is required is when the shoes
are replaced, removed for access to other parts, or
when one or both drums are replaced.
Adjustment can be made with a standard brake
gauge or with adjusting tool . Adjustment is per-
formed with the complete brake assembly installed
on the backing plate.
ADJUSTMENT WITH BRAKE GAUGE
(1) Be sure parking brakes are fully released.
(2) Raise rear of vehicle and remove wheels and
brake drums.
(3) Verify that left and right automatic adjuster
levers and cables are properly connected.
(4) Insert brake gauge in drum. Expand gauge
until gauge inner legs contact drum braking surface.
Then lock gauge in position (Fig. 61).
(5) Reverse gauge and install it on brake shoes.
Position gauge legs at shoe centers as shown (Fig.
62). If gauge does not fit (too loose/too tight), adjust
shoes.
(6) Pull shoe adjuster lever away from adjuster
screw star wheel.(7) Turn adjuster screw star wheel (by hand) to
expand or retract brake shoes. Continue adjustment
until gauge outside legs are light drag-fit on shoes.
(8) Install brake drums and wheels and lower
vehicle.
(9) Drive vehicle and make one forward stop fol-
lowed by one reverse stop. Repeat procedure 8-10
times to operate automatic adjusters and equalize
adjustment.
NOTE: Bring vehicle to complete standstill at each
stop. Incomplete, rolling stops will not activate
automatic adjusters.
Fig. 60 Shoe Contact Surfaces
1 - ANCHOR PIN
2 - SUPPORT PLATE
3 - SHOE CONTACT SURFACES
Fig. 61 Adjusting Gauge On Drum
1 - BRAKE GAUGE
2 - BRAKE DRUM
Fig. 62 Adjusting Gauge On Brake Shoes
1 - BRAKE GAUGE
2 - BRAKE SHOES
5 - 34 BRAKESBR/BE
DRUM (Continued)

DIAGNOSIS CHART
CONDITION POSSIBLE CAUSES CORRECTION
Disc facing worn out 1. Normal wear. 1. Replace cover and disc.
2. Driver frequently rides (slips) the
clutch. Results in rapid overheating
and wear.2. Replace cover and disc.
3. Insufficient clutch cover
diaphragm spring tension.3. Replace cover and disc.
Clutch disc facing contaminated with
oil, grease, or clutch fluid.1. Leak at rear main engine seal or
transmission input shaft seal.1. Replace appropriate seal.
2. Excessive amount of grease
applied to the input shaft splines.2. Remove grease and apply the
correct amount of grease.
3. Road splash, water entering
housing.3. Replace clutch disc. Clean clutch
cover and reuse if in good condition.
4. Slave cylinder leaking. 4. Replace hydraulic clutch linkage.
Clutch is running partially
disengaged.1. Release bearing sticking or
binding and does not return to the
normal running position.1. Verify failure. Replace the release
bearing and transmission front
bearing retainer as necessary.
Flywheel below minimum thickness
specification.1. Improper flywheel machining.
Flywheel has excessive taper or
excessive material removal.1. Replace flywheel.
Clutch disc, cover and/or diaphragm
spring warped or distorted.1. Rough handling. Impact bent
cover, spring, or disc.1. Replace disc or cover as
necessary.
2. Improper bolt tightening
procedure.2. Tighten clutch cover using proper
procedure.
Facing on flywheel side of disc torn,
gouged, or worn.1. Flywheel surface scored or
nicked.2. Correct surface condition if
possible. Replace flywheel and disc
as necessary.
2. Clutch disc sticking or binding on
transmission input shaft.2. Inspect components and
correct/replace as necessary.
Clutch disc facing burnt. Flywheel
and cover pressure plate surfaces
heavily glazed.1. Frequent operation under high
loads or hard acceleration
conditions.1. Correct condition of flywheel and
pressure plate surface. Replace
clutch cover and disc. Alert driver to
problem cause.
2. Driver frequently rides (slips)
clutch. Results in rapid wear and
overheating of disc and cover.2. Correct condition of flywheel and
pressure plate surface. Replace
clutch cover and disc. Alert driver to
problem cause.
BR/BECLUTCH 6 - 5
CLUTCH (Continued)

shaft speeds and releasing the energy back into the
system when the crankshaft slows down.
DIAGNOSIS AND TESTING - FLYWHEEL
Check flywheel runout whenever misalignment is
suspected. Flywheel runout should not exceed 0.08
mm (0.003 in.). Measure runout at the outer edge of
the flywheel face with a dial indicator. Mount the
indicator on a stud installed in place of one of the fly-
wheel bolts.
Common causes of runout are:
²heat warpage
²improper machining
²incorrect bolt tightening
²improper seating on crankshaft flange shoulder
²foreign material on crankshaft flange
Flywheel machining is not recommended. The fly-
wheel clutch surface is machined to a unique contour
and machining will negate this feature. However,
minor flywheel scoring can be cleaned up by hand with
180 grit emery, or with surface grinding equipment.
Remove only enough material to reduce scoring
(approximately 0.001 - 0.003 in.). Heavy stock removal
isnot recommended.
Replace the flywheel if scoring
is severe and deeper than 0.076 mm (0.003 in.).
Excessive stock removal can result in flywheel crack-
ing or warpage after installation; it can also weaken
the flywheel and interfere with proper clutch release.
Clean the crankshaft flange before mounting the
flywheel. Dirt and grease on the flange surface may
cock the flywheel causing excessive runout. Use new
bolts when remounting a flywheel and secure the
bolts with MopartLock And Seal. Tighten flywheel
bolts to specified torque only. Overtightening can dis-
tort the flywheel hub causing runout.
DISASSEMBLY
NOTE: If the teeth are worn or damaged, the fly-
wheel should be replaced as an assembly. This is
the recommended and preferred method of repair.
In cases where a new flywheel is not readily avail-
able, (V10/Diesel Engine only) a replacement ring
gear can be installed. The following procedure must
be observed to avoid damaging the flywheel and
replacement gear.
WARNING: WEAR PROTECTIVE GOGGLES OR
SAFETY GLASSES WHILE CUTTING RING GEAR.
(1) Mark position of the old gear for alignment ref-
erence on the flywheel. Use a scriber for this pur-
pose.
(2) Remove the old gear by cutting most of the way
through it (at one point) with an abrasive cut-off
wheel. Then complete removal with a cold chisel or
punch.
ASSEMBLY
NOTE: The ring gear is a shrink fit on the flywheel.
This means the gear must be expanded by heating
in order to install it. The method of heating and
expanding the gear is extremely important. Every
surface of the gear must be heated at the same
time to produce uniform expansion. An oven or
similar enclosed heating device must be used. Tem-
perature required for uniform expansion is approxi-
mately 375É F.
CAUTION: Do not use an oxy/acetylene torch to
remove the old gear, or to heat and expand a new
gear. The high temperature of the torch flame can
cause localized heating that will damage the fly-
wheel. In addition, using the torch to heat a replace-
ment gear will cause uneven heating and
expansion. The torch flame can also anneal the
gear teeth resulting in rapid wear and damage after
installation.
WARNING: WEAR PROTECTIVE GOGGLES OR
SAFETY GLASSES AND HEAT RESISTENT GLOVES
WHEN HANDLING A HEATED RING GEAR.
(1) The heated gear must be installed evenly to
avoid misalignment or distortion.
(2) Position and install the heated ring gear on the
flywheel with a shop press and a suitable press
plates.
(3) Place flywheel on work bench and let it cool in
normal shop air. Allow the ring gear to cool down
completely before installation it on the engine.
CAUTION: Do not use water or compressed air to
cool the flywheel. The rapid cooling produced by
water or compressed air will distort or crack the
new gear.
PILOT BEARING
DESCRIPTION
Vehicles equipped with a manual transmission uti-
lize a pilot bearing. This bearing is located in the
back of the engine crankshaft. Depending on the type
of engine or application, the pilot bearing can be a
solid soft metallic bushing or a fully caged needle
bearing. The pilot bearing's main functions are to
support the transmission input shaft, maintain
proper alignment of the clutch assembly and allow
the transmission main shaft to rotate at a different
speed than the engine mounted crankshaft.
BR/BECLUTCH 6 - 17
FLYWHEEL (Continued)

COOLING
TABLE OF CONTENTS
page page
COOLING
DESCRIPTION............................1
OPERATION.............................2
DIAGNOSIS AND TESTING..................4
PRELIMINARY CHECKS...................4
ON-BOARD DIAGNOSTICS (OBD)...........4
COOLING SYSTEM LEAKS................5
COOLING SYSTEM GAS ENGINE...........7
COOLING SYSTEM DIESEL ENGINE........12
STANDARD PROCEDURE..................15
DRAINING COOLING SYSTEM - 3.9L/5.2L/
5.9L/8.0L ENGINES......................15
DRAINING COOLING SYSTEM - 5.9L
DIESEL ENGINE........................15REFILLING COOLING SYSTEM - 3.9L/5.2L/
5.9L/8.0L ENGINES......................15
REFILLING COOLING SYSTEM - 5.9L
DIESEL ENGINE........................15
ADDING ADDITIONAL COOLANT...........16
COOLANT LEVEL CHECK................16
COOLING SYSTEM CLEANING/REVERSE
FLUSHING............................16
COOLANT SELECTION-ADDITIVES.........17
SPECIFICATIONS........................17
SPECIAL TOOLS.........................18
ACCESSORY DRIVE......................19
ENGINE................................39
TRANSMISSION.........................79
COOLING
DESCRIPTIONÐCOOLING SYSTEM FLOW -
3.9L/5.2L/5.9L ENGINE
The cooling system regulates engine operating tem-
perature. It allows the engine to reach normal oper-
ating temperature as quickly as possible. It also
maintains normal operating temperature and pre-
vents overheating.
The cooling system also provides a means of heat-
ing the passenger compartment and cooling the auto-
matic transmission fluid (if equipped). The cooling
system is pressurized and uses a centrifugal water
pump to circulate coolant throughout the system.
An optional factory installed maximum duty cool-
ing package is available on most models. This pack-
age will provide additional cooling capacity forvehicles used under extreme conditions such as
trailer towing in high ambient temperatures (Fig. 1).
DESCRIPTIONÐCOOLING SYSTEM FLOW -
5.9L DIESEL
The diesel engine cooling system consists of (Fig.
2):
²Cross-flow radiator
²Belt driven water pump
²Belt driven mechanical cooling fan
²Thermal viscous fan drive
²Fan shroud
²Radiator pressure cap
²Vertically mounted thermostat
²Coolant reserve/recovery system
²Transmission oil cooler
²Coolant
BR/BECOOLING 7 - 1

OPERATIONÐCOOLING SYSTEM
The cooling system regulates engine operating tem-
perature. It allows the engine to reach normal oper-
ating temperature as quickly as possible. It also
maintains normal operating temperature and pre-
vents overheating.
The cooling system also provides a means of heat-
ing the passenger compartment and cooling the auto-
matic transmission fluid (if equipped). The cooling
system is pressurized and uses a centrifugal water
pump to circulate coolant throughout the system.
An optional factory installed maximum duty cool-
ing package is available on most models. This pack-
age will provide additional cooling capacity for
vehicles used under extreme conditions such as
trailer towing in high ambient temperatures.
DIAGNOSIS AND TESTING - PRELIMINARY
CHECKS
ENGINE COOLING SYSTEM OVERHEATING
Establish what driving conditions caused the com-
plaint. Abnormal loads on the cooling system such as
the following may be the cause:
²PROLONGED IDLE
²VERY HIGH AMBIENT TEMPERATURE
²SLIGHT TAIL WIND AT IDLE
²SLOW TRAFFIC
²TRAFFIC JAMS
²HIGH SPEED OR STEEP GRADES
Driving techniques that avoid overheating are:
²Idle with A/C off when temperature gauge is at
end of normal range.²Increasing engine speed for more air flow is rec-
ommended.
TRAILER TOWING:
Consult Trailer Towing section of owners manual.
Do not exceed limits.
AIR CONDITIONING; ADD-ON OR AFTER MARKET:
A maximum cooling package should have been
ordered with vehicle if add-on or after market A/C is
installed. If not, maximum cooling system compo-
nents should be installed for model involved per
manufacturer's specifications.
RECENT SERVICE OR ACCIDENT REPAIR:
Determine if any recent service has been per-
formed on vehicle that may effect cooling system.
This may be:
²Engine adjustments (incorrect timing)
²Slipping engine accessory drive belt(s)
²Brakes (possibly dragging)
²Changed parts. Incorrect water pump or pump
rotating in wrong direction due to belt not correctly
routed
²Reconditioned radiator or cooling system refill-
ing (possibly under filled or air trapped in system).
NOTE: If investigation reveals none of the previous
items as a cause for an engine overheating com-
plaint, (Refer to 7 - COOLING - DIAGNOSIS AND
TESTING)
DIAGNOSIS AND TESTINGÐON-BOARD
DIAGNOSTICS (OBD)
COOLING SYSTEM RELATED DIAGNOSTICS
The powertrain control module (PCM) has been
programmed to monitor certain cooling system com-
ponents:
²If the engine has remained cool for too long a
period, such as with a stuck open thermostat, a Diag-
nostic Trouble Code (DTC) can be set.
²If an open or shorted condition has developed in
the relay circuit controlling the electric radiator fan,
a Diagnostic Trouble Code (DTC) can be set.
If the problem is sensed in a monitored circuit
often enough to indicated an actual problem, a DTC
is stored. The DTC will be stored in the PCM mem-
ory for eventual display to the service technician.
(Refer to 25 - EMISSIONS CONTROL - DESCRIP-
TION).
Fig. 4 Spring Clamp Size Location
1 - SPRING CLAMP SIZE LOCATION
7 - 4 COOLINGBR/BE
COOLING (Continued)

hoses, gasket edges and heater. Seal small leak holes
with a Sealer Lubricant (or equivalent). Repair leak
holes and inspect system again with pressure
applied.
Drops Quickly:Indicates that serious leakage is
occurring. Examine system for external leakage. If
leaks are not visible, inspect for internal leakage.
Large radiator leak holes should be repaired by a
reputable radiator repair shop.
INTERNAL LEAKAGE INSPECTION
Remove engine oil pan drain plug and drain a
small amount of engine oil. If coolant is present in
the pan, it will drain first because it is heavier than
oil. An alternative method is to operate engine for a
short period to churn the oil. After this is done,
remove engine dipstick and inspect for water glob-
ules. Also inspect transmission dipstick for water
globules and transmission fluid cooler for leakage.
WARNING: WITH RADIATOR PRESSURE TESTER
TOOL INSTALLED ON RADIATOR, DO NOT ALLOW
PRESSURE TO EXCEED 110 KPA (20 PSI). PRES-
SURE WILL BUILD UP QUICKLY IF A COMBUSTION
LEAK IS PRESENT. TO RELEASE PRESSURE,
ROCK TESTER FROM SIDE TO SIDE. WHEN
REMOVING TESTER, DO NOT TURN TESTER MORE
THAN 1/2 TURN IF SYSTEM IS UNDER PRESSURE.
Operate engine without pressure cap on radiator
until thermostat opens. Attach a Pressure Tester to
filler neck. If pressure builds up quickly it indicates a
combustion leak exists. This is usually the result of a
cylinder head gasket leak or crack in engine. Repair
as necessary.
If there is not an immediate pressure increase,
pump the Pressure Tester. Do this until indicated
pressure is within system range of 110 kPa (16 psi).
Fluctuation of gauge pointer indicates compression or
combustion leakage into cooling system.
Because the vehicle is equipped with a catalytic
converter,do notremove spark plug cables or short
out cylinders to isolate compression leak.If the needle on dial of pressure tester does not
fluctuate, race engine a few times to check for an
abnormal amount of coolant or steam. This would be
emitting from exhaust pipe. Coolant or steam from
exhaust pipe may indicate a faulty cylinder head gas-
ket, cracked engine cylinder block or cylinder head.
A convenient check for exhaust gas leakage into
cooling system is provided by a commercially avail-
able Block Leak Check tool. Follow manufacturers
instructions when using this product.COMBUSTION LEAKAGE TESTÐWITHOUT
PRESSURE TESTER
DO NOT WASTE reusable coolant. If solution is
clean, drain coolant into a clean container for reuse.
WARNING: DO NOT REMOVE CYLINDER BLOCK
DRAIN PLUGS OR LOOSEN RADIATOR DRAIN-
COCK WITH SYSTEM HOT AND UNDER PRESSURE.
SERIOUS BURNS FROM COOLANT CAN OCCUR.
Drain sufficient coolant to allow thermostat
removal. (Refer to 7 - COOLING/ENGINE/ENGINE
COOLANT THERMOSTAT - REMOVAL). Remove
accessory drive belt (Refer to 7 - COOLING/ACCES-
SORY DRIVE/DRIVE BELTS - REMOVAL).
Add coolant to radiator to bring level to within 6.3
mm (1/4 in) of top of thermostat housing.
CAUTION: Avoid overheating. Do not operate
engine for an excessive period of time. Open drain-
cock immediately after test to eliminate boil over.
Start engine and accelerate rapidly three times, to
approximately 3000 rpm while observing coolant. If
internal engine combustion gases are leaking into
cooling system, bubbles will appear in coolant. If bub-
bles do not appear, internal combustion gas leakage
is not present.
7 - 6 COOLINGBR/BE
COOLING (Continued)