coating carefully. Do not reuse either part if the coat-
ing is damaged.
Inspect the governor weight spring for distortion.
Replace the spring, if distorted, collapsed, or broken.
Clean the filter in solvent and dry it with compressed
air. Replace the filter, if damaged. Inspect the park
gear for chipped or worn gear teeth or damaged ring
grooves. Replace the gear, if damaged.
Check the teeth on the park gear for wear or dam-
age. Replace the gear if necessary. Inspect the metal
seal rings on the park gear hub. Replace the rings
only if severely worn, or broken.
OIL PUMP
DESCRIPTION
The oil pump is located in the pump housing inside
the bell housing of the transmission case. The oil
pump consists of an inner and outer gear, a housing,
and a cover that also serves as the reaction shaft
support (Fig. 182).
OPERATION
As the torque converter rotates, the converter hub
rotates the inner and outer gears. As the gears
rotate, the clearance between the gear teeth
increases in the crescent area, and creates a suction
at the inlet side of the pump. This suction drawsfluid through the pump inlet from the oil pan. As the
clearance between the gear teeth in the crescent area
decreases, it forces pressurized fluid into the pump
outlet and to the valve body.
STANDARD PROCEDURE - OIL PUMP VOLUME
CHECK
Measuring the oil pump output volume will deter-
mine if sufficient oil flow to the transmission oil
cooler exists, and whether or not an internal trans-
mission failure is present.
Verify that the transmission fluid is at the proper
level. Refer to the Fluid Level Check procedure in
this section. If necessary, fill the transmission to the
proper level with MopartATF +4, type 9602, Auto-
matic Transmission Fluid.
(1) Using hose cutters or a suitable blade, cut the
To coolerline off flush with the cooler inlet fitting
and place a collecting container under the open line.
CAUTION: With the fluid set at the proper level,
fluid collection should not exceed (1) quart or inter-
nal damage to the transmission may occur.
(2) Run the engineat curb idle speed, with the
shift selector in neutral.
(3) If one quart of transmission fluid is collected in
the container in 20 seconds or less, oil pump flow vol-
ume is within acceptable limits. If fluid flow is inter-
Fig. 182 Oil Pump Assembly
1 - REACTION SHAFT SUPPORT
2 - INNER GEAR
3 - PUMP BODY4 - PUMP BUSHING
5 - OUTER GEAR
RS31TH AUTOMATIC TRANSAXLE21 - 105
GOVERNOR (Continued)
ProCarManuals.com
Inspect for the following:
²Verify correct (OEM) wheel and tire, as well as
correct wheel weights. Aluminum wheels require
unique wheel weights. They are designed to fit the
contour of the wheel (Fig. 1).
²Inspect tires and wheels for damage, mud pack-
ing and unusual wear; correct as necessary.
²Check and adjust tire air pressure to the pres-
sure listed on the label attached to the rear face of
the driver's door.
ROAD TEST
Road test vehicle on a smooth road for a least five
miles to warm tires (remove any flat spots). Lightly
place hands on steering wheel at the 10:00 and 2:00
positions while slowly sweeping up and down from 90 to
110 km/h (55 to 70 mph) where legal speed limits allow.
Observe the steering wheel for:
²Visual Nibble (oscillation: clockwise/counter-
clockwise, usually due to tire imbalance)
²Visual Buzziness (high frequency, rapid vibra-
tion up and down)
To rule out vibrations due to brakes or powertrain:
²Lightly apply brakes at speed; if vibration occurs
or is enhanced, vibration is likely due to causes other
than tire and wheel assemblies.
²
Shift transmission into neutral while vibration is
occurring; if vibration is eliminated, vibration is likely
due to causes other than tire and wheel assemblies.
For brake vibrations, (Refer to 5 - BRAKES -
BASE/HYDRAULIC/MECHANICAL/ROTORS -
DIAGNOSIS AND TESTING).
For powertrain vibrations, (Refer to 3 - DIFFEREN-
TIAL & DRIVELINE - DIAGNOSIS AND TESTING).
For tire and wheel assembly vibrations, continue
with this diagnosis and testing procedure.
TIRE AND WHEEL BALANCE
(1) Balance the tire and wheel assemblies as nec-
essary following the wheel balancer manufacturer's
instructions and using the information listed in Stan-
dard Procedure - Tire And Wheel Balance. (Refer to
22 - TIRES/WHEELS - STANDARD PROCEDURE)
(2) Road test the vehicle for at least 5 miles, fol-
lowing the format described in Road Test.
(3) If the vibration persists, continue with this
diagnosis and testing procedure.
TIRE AND WHEEL RUNOUT/MATCH MOUNTING
(1)System Radial Runout.This on-the-vehicle
system check will measure the radial runout includ-
ing the hub, wheel and tire.
(a) Raise vehicle so tires clear floor. (Refer to
LUBRICATION & MAINTENANCE/HOISTING -
STANDARD PROCEDURE)
(b) Apply masking tape around the circumfer-
ence of the tire in the locations to be measured
(Fig. 2). Do not overlap the tape.
(c) Check system runout using Dial Indicator
Set, Special Tool C-3339A with 25-W wheel, or
equivalent. Place the end of the indicator against
each taped area (one at a time) (Fig. 2) and rotate
the tire and wheel. System radial runout should
not exceed 0.76 mm (0.030 inch) with no tread
ªdipsº or ªsteps.º Tread ªdipsº and ªstepsº can be
identified by spikes of the dial indicator gauge.
²Tread9dips9; Rapid decrease then increase in
dial indicator reading over 101.6 mm (4.0 inch) of
tread circumference.
²Tread9steps9; Rapid decrease or increase in dial
indicator reading over 101.6 mm (4.0 inch) of tread
circumference.
(d) If system runout is excessive, re-index the
tire and wheel assembly on the hub. Remove
assembly from vehicle and install it back on the
hub two studs over from original mounting posi-
tion. If re-indexing the tire and wheel assembly
corrects or reduces system runout, check hub
runout and repair as necessary (Refer to 5 -
BRAKES - BASE/HYDRAULIC/MECHANICAL/
ROTORS - DIAGNOSIS AND TESTING).
(e) If system runout is still excessive, continue
with this diagnosis and testing procedure.
(2)Tire and Wheel Assembly Radial Runout.
This radial runout check is performed with the tire
and wheel assembly off the vehicle.
(a) Remove tire and wheel assembly from vehicle
and install it on a suitable wheel balancer.
(b) Check system runout using Dial Indicator
Set, Special Tool C-3339A with 25-W wheel, or
equivalent. Place the end of the indicator against
each taped area (one at a time) (Fig. 2) and rotate
the tire and wheel. Radial runout should not
Fig. 1 Aluminum Wheel Weight
1 - TIRE
2 - WHEEL
3 - WHEEL WEIGHT
22 - 2 TIRES/WHEELSRS
TIRES/WHEELS (Continued)
ProCarManuals.com
lines. Radial force measurements above the reference
value may not always result in a ride disturbance,
nor do they automatically mean the assembly compo-
nents are out of specification. Do not replace compo-
nents based on radial force values alone. Balancing,
runout diagnosis, re-indexing, and subjective road
testing must be performed as outlined in previous
sections of this diagnosis and testing procedure.
Use the Radial Force equipment to identify suspect
assemblies and minimize the radial forces. After all
suspect assemblies are optimized, reinstall the
assemblies and road test the vehicle. If a disturbance
still exists and all other vibration diagnostic proce-
dures have been completed, replace one tire or one
wheel at a time, starting with the assembly having
the highest force variation. Be sure to minimize each
new assembly. Road test the vehicle following each
replacement. Continue this process until the distur-
bance is resolved.
NOTE: When using Radial Force equipment, it is
critically important to set proper tire inflation pres-
sure and ensure centering of the wheel on the
equipment spindle.
RADIAL FORCE VARIATION REFERENCE
VALUES
DESCRIPTION SPECIFICATION
Total Radial Force
Variation (RFV)Less Than 22 Lbs. 2
Lbs.
Radial First Harmonic
(R1H)Less Than 16 Lbs. 2
Lbs.
Radial Second Harmonic
(R2H)Less Than 12 Lbs. 2
Lbs.
STANDARD PROCEDURE
STANDARD PROCEDURE - TIRE AND WHEEL
BALANCE
NOTE: Balance equipment must be calibrated and
maintained per equipment manufacturer's specifica-
tions.
Wheel balancing can be accomplished with either
on-vehicle or off-vehicle equipment.
NOTE: If using on-vehicle balancing equipment, on
the driving axle, remove the opposite wheel and tire
assembly.
It is recommended that a two-plane dynamic bal-
ancer be used when a wheel and tire assemblyrequires balancing. A static balancer should only be
used when a two-plane balancer is not available.
Balance wheel and tire assemblies dynamically and
statically to less than 0.25 (
1¤4) ounce.
For static balancing, find location of heavy spot
causing imbalance. Counter balance wheel directly
opposite the heavy spot. Determine weight required
to counterbalance the area of imbalance. Place half of
this weight on theinnerrim flange and the other
half on theouterrim flange (Fig. 8).
For dynamic balancing, the balance equipment is
designed to indicate the location and amount of
weight to be applied to both the inner and outer rim
flanges (Fig. 9).
The aluminum wheels on this vehicle use a unique
wheel weight (Fig. 10). This wheel weight is designed
to fit the contoured surface of the wheel (Fig. 10).
When balancing an aluminum wheel, this wheel
weight must be used. Do not use any other type of
wheel weight. It will not properly fit the contour of
the wheel.
Always verify the Balance. When using off-vehicle
equipment, rotate assembly 180 degrees on balance
equipment to verify balance. Variation should not be
more than 0.125 (
1¤8) ounce. If variation is more than
0.125 ounce, balancing equipment could be malfunc-
tioning.
If difficult to balance, break down the wheel and
tire assembly and check for loose debris inside tire.
Prior to disassembly, mark (index) the tire at the
valve stem. Use this mark in order to remount the
tire in its original orientation with respect to the
wheel.
STANDARD PROCEDURE - TIRE AND WHEEL
MATCH MOUNTING
Wheels and tires are match mounted at the factory.
This means that the high spot of the tire is matched
to the low spot on the wheel rim. This technique is
used to reduce runout in the wheel and tire assem-
bly. The high spot on the tire is marked with a paint
mark or a bright colored adhesive label on the out-
board sidewall. The low spot on the wheel is identi-
fied with a label on the outside of the rim and a dot
or line in the drop well area of the rim (inside where
the tire mounts). If the outside label has been
removed, the tire will have to be removed to locate
the dot or line on the inside of the rim. The tire can
then be match mounted to the tire.
Information on match mounting the tire to the
wheel can be found in Tire and Wheel Runout/Match
Mounting, items (2) through (5), within Diagnosis
And Testing - Tire And Wheel Vibration. (Refer to 22
- TIRES/WHEELS - DIAGNOSIS AND TESTING)
RSTIRES/WHEELS22-5
TIRES/WHEELS (Continued)
ProCarManuals.com
Fig. 8 Static Unbalance & Balance
1 - HEAVY SPOT 4 - CORRECTIVE WEIGHT LOCATION
2 - CENTER LINE OF SPINDLE 5 - TIRE OR WHEEL TRAMP, OR WHEEL HOP
3 - ADD BALANCE WEIGHTS HERE
Fig. 9 Dynamic Unbalance & Balance
1 - CENTER LINE OF SPINDLE 3 - CORRECTIVE WEIGHT LOCATION
2 - ADD BALANCE WEIGHTS HERE 4 - HEAVY SPOT WHEEL SHIMMY AND VIBRATION
22 - 6 TIRES/WHEELSRS
TIRES/WHEELS (Continued)
ProCarManuals.com
STANDARD PROCEDURE - TIRE AND WHEEL
ROTATION
NON-DIRECTIONAL TREAD PATTERN TIRES
Tires on the front and rear axles operate at differ-
ent loads and perform different functions. For these
reasons, they wear at unequal rates, and tend to
develop irregular wear patterns. These effects can be
reduced by timely rotation of tires. The benefits of
rotation are especially worthwhile. Rotation will
increase tread life, help to maintain mud, snow, and
wet traction levels, and contribute to a smooth, quiet
ride.
The suggested rotation method is the forward-cross
tire rotation method (Fig. 11). This method takes
advantage of current tire industry practice which
allows rotation of radial-ply tires. Other rotation
methods may be used, but may not have all the ben-
efits of the recommended method.
NOTE: Only the 4 tire rotation method may be used
if the vehicle is equipped with a low mileage or tem-
porary spare tire.
DIRECTIONAL TREAD PATTERN TIRES
Some vehicles are fitted with special high-perfor-
mance tires having a directional tread pattern. These
tires are designed to improve traction on wet pave-
ment. To obtain the full benefits of this design, the
tires must be installed so that they rotate in the cor-
rect direction. This is indicated by arrows on the tire
sidewalls.When wheels and tires are being installed, extra
care is needed to ensure that this direction of rota-
tion is maintained.
Refer to Owner's Manual for rotation schedule.
REMOVAL
REMOVAL - TIRE AND WHEEL ASSEMBLY
(ALUMINUM WHEEL)
(1) Raise the vehicle so the tire and wheel assem-
bly clears ground level.
(2) Remove the 5 wheel mounting nuts from the
studs.
(3) Remove the tire and wheel from the hub.
REMOVAL - TIRE AND WHEEL ASSEMBLY
(STEEL WHEEL)
(1) Raise the vehicle so the tire and wheel assem-
bly clears ground level.
(2) Noting the location of the valve stem in rela-
tionship to the wheel mounting nuts, remove the
three wheel mounting nuts securing the wheel cover
to the wheel and hub (Fig. 12).
CAUTION: When removing the wheel cover, do not
pry the wheel cover from the wheel. This can result
in damage to the wheel cover. The wheel cover is
removed by pulling it off the wheel by hand.
Fig. 10 Aluminum Wheel Weight
1 - TIRE
2 - WHEEL
3 - WHEEL WEIGHT
Fig. 11 Forward-Cross Tire Rotation Method
RSTIRES/WHEELS22-7
TIRES/WHEELS (Continued)
ProCarManuals.com
Over inflation causes rapid center wear and loss of
the tire's ability to cushion shocks (Fig. 26).
STANDARD PROCEDURE - TIRE PRESSURE
FOR HIGH SPEED OPERATION
DaimlerChrysler Corporation advocates driving at
safe speeds within posted speed limits. Where speed
limits allow the vehicle to be driven at high speeds,
correct tire inflation pressure is very important.
Vehicles loaded to maximum capacity should not be
driven at continuous speeds over 120 km/h (75 mph).
Never exceed the maximum speed capacity of the
tire. For information on tire identification and speed
ratings, (Refer to 22 - TIRES/WHEELS/TIRES -
DESCRIPTION).
STANDARD PROCEDURE - TIRE LEAK
REPAIRING
For proper repairing, a radial tire must be removed
from the wheel. Repairs should only be made if the
defect, or puncture, is in the tread area (Fig. 27). The
tire should be replaced if the puncture is located in
the sidewall.
Deflate tire completely before attempting to dis-
mount the tire from the wheel.Use a lubricant
such as a mild soap solution when dismounting
or mounting tire.Use tools free of burrs or sharp
edges which could damage the tire or wheel rim.
Before mounting tire on wheel, make sure all rust
is removed from the rim bead and repaint if neces-
sary.
Install wheel on vehicle, and progressively tighten
the 5 wheel nuts to a torque of 135 N´m (100 ft. lbs.).
CLEANING - TIRES
Before delivery of a vehicle, remove the protective
coating on the tires with white sidewalls or raisedwhite letters. To remove the protective coating, apply
warm water and let it soak for a few minutes. After-
wards, scrub the coating away with a soft bristle
brush. Steam cleaning may also be used to remove
the coating.
CAUTION: DO NOT use gasoline, mineral oil, oil-
based solvent or a wire brush for cleaning.
WHEELS
DESCRIPTION - WHEEL
Original equipment wheels are designed for proper
operation at all loads up to the specified maximum
vehicle capacity.
All models use either steel or aluminum drop-cen-
ter wheels. Every wheel has raised sections between
the rim flanges and rim drop well called safety
humps (Fig. 28). Initial inflation of the tires forces
the bead over these raised sections. In case of air
loss, the safety humps hold the tire in position on the
wheel until the vehicle can be brought to a safe stop.
Cast aluminum wheels require special balance
weights to fit on the flange of the rim (Fig. 29).
When wheel alignment is necessary on a vehicle
with cast aluminum wheels, special wheel clamps are
required to avoid damage to the wheel's finish.
The wheel studs and nuts are designed for specific
wheel applications and must be replaced with equiv-
alent parts.
Fig. 26 Over Inflation Wear
1 - THIN TIRE TREAD AREAFig. 27 Tire Repair Area
1 - REPAIRABLE AREA
RSTIRES/WHEELS22-17
TIRES (Continued)
ProCarManuals.com
All aluminum wheels have wheel mounting (lug)
nuts with an enlarged nose. This enlarged nose is
necessary to ensure proper retention of the wheels.
DIAGNOSIS AND TESTING - WHEEL
INSPECTION
Inspect wheels for:
²Excessive runout
²Dents, cracks or irregular bends
²Damaged wheel stud (lug) holes
²Air Leaks
NOTE: Do not attempt to repair a wheel by hammer-
ing, heating or welding.
If a wheel is damaged, an original equipment
replacement wheel should be used. When obtaining
replacement wheels, they must be equivalent in load
carrying capacity. The diameter, width, offset, pilot
hole and bolt circle of the wheel should be the same
as the original wheel.
WARNING: FAILURE TO USE EQUIVALENT
REPLACEMENT WHEELS MAY ADVERSELY
AFFECT THE SAFETY AND HANDLING OF THE
VEHICLE.
WARNING: REPLACEMENT WITH USED WHEELS IS
NOT RECOMMENDED. THE SERVICE HISTORY OF
THE WHEEL MAY HAVE INCLUDED SEVERE TREAT-
MENT OR VERY HIGH MILEAGE. THE RIM COULD
FAIL WITHOUT WARNING.
CLEANING - ALUMINUM WHEEL CARE
Chrome plated and painted aluminum wheels
should be cleaned regularly using mild soap and
water to maintain their luster and to prevent corro-
sion.
Care must be taken in the selection of tire and
wheel cleaning chemicals and equipment to prevent
damage to the wheels. Any of the ªDO NOT USEº
items listed below WILL damage chrome plated and
painted aluminum wheels.
DO NOT USE:
²any abrasive metal cleaner
²any abrasive cleaning pad or brush
²any cleaner that contains an acid (this will
immediately react with and discolor the chromium
surface)
²chrome polish (unless it is buffed off immedi-
ately after application)
²oven cleaner
²a car wash that uses carbide-tipped wheel clean-
ing brushes
Fig. 28 Safety Rim
1 - TIRE
2 - WELL
3 - SAFETY HUMPS
4 - FLANGE
Fig. 29 Styled Aluminum Wheel Weight
1 - TIRE
2 - WHEEL
3 - STYLED WHEEL WEIGHT
22 - 18 TIRES/WHEELSRS
WHEELS (Continued)
ProCarManuals.com
(7) With the DRBIIItin Cabin Heater, select Sys-
tem Tests and Dosing Pump Prime. Allow the Dosing
Pump to run for the full 45 second cycle time. When
the 45 second cycle is complete, press Page Back on
the DRBIIItkey pad to exit the Dosing Pump Prime.
The Dosing Pump priming procedure is now com-
plete.
HEATER UNIT
REMOVAL
WARNING: ALLOW THE DCHA TO COOL BEFORE
PERFORMING A COMPONENT INSPECTION/REPAIR
OR REPLACEMENT. FAILURE TO FOLLOW THESE
INSTRUCTIONS MAY RESULT IN PERSONAL
INJURY.
WARNING: ALLOW THE EXHAUST SYSTEM TO
COOL BEFORE PERFORMING A COMPONENT
INSPECTION/REPAIR OR REPLACEMENT. FAILURE
TO FOLLOW THESE INSTRUCTION MAY RESULT IN
PERSONAL INJURY.
(1) Elevate the vehicle on a hoist/lift taking note of
heater exhaust tube flexible section.
(2) Drain cooling system(Refer to 7 - COOLING -
STANDARD PROCEDURE).
(3) Carefully open one hose to the underbody tube
assembly and drain the remaining coolant. A salvage
hose is a good idea to control the residual coolant, as
flow will occur from both the heater and the hose and
tube assemblies.
(4) Remove the second hose from the underbody
hose and tube assembly.
(5) Loosen the hose and tube assembly from the
toe-board cross member at two locations.
(6) Disconnect the electrical connector from the
body harness near the toe board cross member and
rail.
(7) Remove the wiring harness from the toe board
cross member(Refer to 24 - HEATING & AIR CON-
DITIONING/CABIN HEATER/HEATER UNIT -
REMOVAL).
(8) Open the fuel fill cap. Disconnect the rubber
fuel hose between the body tube assembly and the
fuel pump nipple at the body tube joint. A minimal
amount of fuel may flow from the open port.
NOTE: Utilize an approved fuel storage container to
catch any residual fuel.
(9) Loosen the two M8 fasteners at the rail. Take
care to notice that the exhaust tube bracket tab is on
top of the heater bracket.(10) Remove the heater exhaust tube flex section
from the exhaust tube by loosening the M6 bolt of
the clamp assembly. Remove the hose from the
exhaust tube. Removal of the rail tube assembly may
aid in this service operation.(Refer to 24 - HEATING
& AIR CONDITIONING/CABIN HEATER/EXHAUST
TUBE - REMOVAL).
(11) Remove seat hex nut at the heater mounting
flange to cross member.
(12) Loosen the remaining M6 and M8 fasteners
which mount the exhaust tube assembly to the vehi-
cle.
(a) Install a suitable cabin heater support device
under the cabin heater and secure the cabin heater
to the device.
(13) Loosen the remaining three M6 fasteners to
the cross members.
(14) Remove the loosened fasteners that support
the heater while supporting the weight of the heater.
(15) Swing the unit mounting bracket from
between the exhaust bracket and rail mounting loca-
tion. Drain any residual coolant from the heater unit.
(16) Lower the cabin heater and remove from the
supporting device and place on a suitable work area.
INSTALLATION
(1) Install the unit mounting bracket between the
exhaust bracket and the rail mounting location.
(2) Install the fasteners that support the heater
while supporting the weight of the heater.
(3) Install the three M6 fasteners to the cross
members. Tighten the M6 fasteners to 7 Nm (5 ft.
lbs.).
(4) Tighten the remaining M6 fasteners to 7 Nm (5
ft. lbs.) and the M8 fasteners to 23 Nm (17 ft. lbs.)
which mount the exhaust tube assembly to the vehi-
cle.
(5) Install the seat hex nut at the heater mounting
flange to the cross members. Tighten to 60 Nm (44 ft.
lbs.)
(6) Install the heater exhaust tube flex section to
the exhaust tube by tightening the M6 bolt of the
clamp assembly. Install the hose to the exhaust tube.
(7) Tighten the two M8 fasteners at the rail to 23
Nm (17 ft. lbs.). Taking care so that the exhaust tube
bracket tab is on the top of the heater bracket.
(8) Install the wiring harness(Refer to 24 - HEAT-
ING & AIR CONDITIONING/CABIN HEATER/
HEATER UNIT - INSTALLATION).
(9) Tighten the hose and tube assembly to the toe-
board cross member at two locations.
(10) Install the second hose to the underbody hose
and tube assembly.
(11) Connect the rubber fuel hose between the
body tube assembly and the fuel pump nipple at the
body tube joint. Close the fuel fill cap.
24 - 114 DIESEL SUPPLEMENTAL HEATER - DCHA - BUXRS
FUEL LINE (Continued)
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