weight CHEVROLET DYNASTY 1993 Owner's Guide
Page 1700 of 2438
SERVICE PROCEDURES INDEX
page page
Exhaust Pipes, Mufflers and Tailpipes .......... 4
Intake and Exhaust Manifolds ServiceÐTBI Engine.6Intake and Exhaust ManifoldsÐFlexible Fuel Engine.7
Intake and Exhaust ManifoldsÐTBI Engine ...... 5
Intake/Exhaust Manifold ServiceÐ3.0L Engine . . . 13
Intake/Exhaust Manifold ServiceÐ3.3/3.8L Engines.19
Intake/Exhaust Manifolds and Turbocharger ServiceÐTurbo III Engine .................. 9
Intake/Exhaust Manifolds ServiceÐFlexible Fuel Engines ............................... 7
EXHAUST PIPES, MUFFLERS AND TAILPIPES
REMOVAL
(1) Raise vehicle on hoist and apply penetrating oil
to clamp bolts and nuts of component being removed. (2) Tail pipes are integral with the muffler (Fig. 5).
Remove clamp at slip joint. Separate at slip joint. (3) Remove clamps and supports (Figs. 6, 7, 8, and 9)
from exhaust system to permit alignment of parts
during assembly. (4) When removing tailpipe, raise rear of vehicle to
relieve body weight from rear springs to provide clear-
ance between pipe and rear axle parts. (5) Clean ends of pipes and/or muffler to assure
mating of all parts. Discard broken or worn insulators,
rusted clamps, supports and attaching parts. When replacement is required on any compo-
nent of the exhaust system, it is most important
that original equipment parts (or their equiva-
lent) be used;
² To insure proper alignment with other parts in the
system.
² Provide acceptable exhaust noise levels and does not
change exhaust system back pressure that could affect
emissions and performance.
INSTALLATION
(1) Assemble ball joint connection pipes, supports
and clamps loosely to permit alignment of all parts.
Fig. 6 Insulator Tail Pipe and Muffler Support
Fig. 7 Underfloor Converter or Extension Pipe SupportÐ2 Places
Fig. 5 Tail Pipe with MufflerÐTypical
11 - 4 EXHAUST SYSTEM AND INTAKE MANIFOLD Ä
Page 1758 of 2438
INSTALLATION
WARNING: FUEL TANKS DESIGNED FOR GASO-
LINE ONLY VEHICLES CANNOT BE USED ON
FLEXIBLE FUEL AA-BODY VEHICLES. WHEN SER-
VICING THE FUEL SYSTEM OF A FLEXIBLE FUEL
VEHICLE, ONLY USE ORIGINAL EQUIPMENT OR
EQUIVALENT REPLACEMENT COMPONENTS. (1) Position fuel tank on transmission jack. Con-
nect vapor separator/rollover valve hose and position
insulator pad on fuel tank. Position vapor vent so
that it is not pinched between tank and floor pan
during installation. (2) Raise tank and fuel filler tube carefully into
position. Use a light coating of power steering fluid
to ease fuel filler tube installation. Ensure filler tube
grommet is not damaged. Verify that the tube is in-
stalled correctly. (3) Tighten fuel tank strap nuts to 23 N Im (250 in.
lbs.) torque. Remove transmission jack. Ensure
straps are not twisted or bent. (4) Lubricate the metal tubes on the fuel pump
with clean 30 weight engine oil. Install the quick
connect fuel fittings. Refer to Quick Connect Fittings
in the Fuel Delivery section of this Group. (5) Attach electrical connector to fuel pump mod-
ule and level sensor unit. (6) Lower the vehicle.
(7) Attach filler tube to filler neck opening in
quarter panel. Tighten quarter panel screws to 2
N Im (17 in. lbs.) torque.
(8) Fill fuel tank, install filler cap, and connect
battery cable.
CAUTION: When using the ASD Fuel System Test,
the Auto Shutdown (ASD) Relay remains energized
for either 7 minutes, until the test is stopped, or un-
til the ignition switch is turned to the Off position.
(9) Use the DRBII scan tool ASD Fuel System Test
to pressurize the fuel system. Check for leaks.
FUEL PUMP MODULE
Refer to the Fuel Delivery section of this group.
METHANOL CONCENTRATION SENSOR
Refer to the Fuel Delivery section of this group.
FUEL RESERVOIR
The fuel reservoir is internal to the fuel pump as-
sembly (Fig. 6). The purpose is to provide fuel at the
fuel pump intake during all driving conditions, espe-
cially when low fuel levels are present.
FUEL TANK LEVEL SENSOR
DIAGNOSIS
This procedure test the resistance of the level sen-
sor itself. It does not test the level sensor circuit. Re-
fer to Group 8W, Wiring Diagrams for circuit
identification and Group 8E, Instrument Panel and
Gauges for fuel gauge information. The level sensor is a variable resistor. Its resis-
tance changes with the amount of fuel in the tank.
The float arm attached to the sensor moves as the
fuel level changes. To test the level sensor, connect
an ohmmeter across the sensor signal and sensor
ground terminals of the fuel level sensor connector
(Fig. 7 or Fig. 8). Move the float lever to the full stop
and empty stop positions shown in the resistance
chart (Fig. 7 or Fig. 8). Record the resistance at each
point. Replace the level sensor if the resistance is not
within specifications. The low fuel warning light specifications determine
if the level sensor portion of the warning light circuit
functions properly. It does not test the complete
warning light circuit. Refer to Group 8W, Wiring Diagrams for circuit
identification and Group 8E, Instrument Panel and
Gauges for fuel gauge information.
REMOVAL
WARNING: RELEASE FUEL SYSTEM PRESSURE
BEFORE SERVICING FUEL SYSTEM COMPONENTS.
WHEN SERVICING FLEXIBLE FUEL VEHICLES,
WEAR METHANOL RESISTANT GLOVES AND EYE
PROTECTION AND AVOID BREATHING FUMES. DO
NOT ALLOW METHANOL/GASOLINE MIXTURES TO
CONTACT SKIN. SERVICE VEHICLES IN WELL VEN-
TILATED AREAS AND AVOID IGNITION SOURCES.
NEVER SMOKE WHILE SERVICING THE VEHICLE.
Fig. 6 Fuel Reservoir
14 - 18 FUEL SYSTEMS Ä
Page 1790 of 2438
(5) Remove throttle cable. If equipped, remove the
speed control and transaxle kickdown cables. (6) Remove return spring.
(7) Loosen fuel tube clamp on valve cover (Fig. 4).
(8) Wipe quick connect fittings to remove any dirt.
Remove fuel intake and return tubes. Refer to Fuel
Hoses, Clamps and Quick Connect Fittings in the
Fuel Delivery Section of this Group. Place a shop
towel under the connections to absorb any fuel spilled. (9) Remove throttle body mounting screws and lift
throttle body from vehicle. Remove throttle body gas-
ket from intake manifold.
INSTALLATION
(1) Using a new gasket, install throttle body and
tighten mounting screws to 20 N Im (175 in. lbs.)
torque. (2) Lubricate the ends of the fuel supply and return
tubes with clean 30 weight oil. Connect fuel lines to
quick connect fittings. Refer to Fuel Hoses, Clamps
and Quick Connect Fittings in the Fuel Delivery
Section of this Group . After the fuel tubes are
connected to the fittings, pull on the tubes to ensure
that they are fully inserted and locked into position. (3) Tighten the fuel tube clamp on the valve cover.
(4) Install return spring.
(5) Install throttle cable. If equipped, install kick-
down and speed control cables. (6) Install wiring connectors and vacuum hoses.
(7) Install air cleaner.
(8) Reconnect negative battery cable.
CAUTION: When using the ASD Fuel System Test, the
Auto Shutdown (ASD) Relay remains energized for
either 7 minutes, until the test is stopped, or until the
ignition switch is turned to the Off position. (9) With the ignition key in ON position, access the
DRBII scan tool ASD Fuel System Test to pressurize
the fuel system. Check for leaks.
FUEL FITTING
REMOVAL
(1) Remove air cleaner assembly.
(2) Perform Fuel System Pressure Release proce-
dure. (3) Disconnect negative battery cable.
(4) Loosen fuel tube clamp on valve cover.
(5) Wipe any dirt from around quick connect fittings.
(Fig. 5) Place a shop towel under the connections to
catch any spilled fuel. Remove fuel tubes from quick
connect fittings. Refer to Fuel Hoses, Clamps and
Quick Connect Fittings in the Fuel Delivery Sec-
tion of this Group .
(6) Remove each fitting from throttle body and note
inlet diameter. Remove copper washers.
INSTALLATION
(1) Replace copper washers with new washers.
(2) Install fuel fittings in proper ports and tighten to
20 N Im (175 in. lbs.) torque.
(3) Lubricate ends of the fuel tubes with 30 weight
oil. Insert the tubes into the quick connect fittings.
Refer to Fuel Hoses, Clamps and Quick Connect
Fittings in the Fuel Delivery Section of this
Group . After the fuel tubes are connected to the
fittings, pull on the tubes to ensure that they are fully
inserted and locked into position. (4) Tighten fuel tube clamp on valve cover.
(5) Reconnect negative battery cable.
Fig. 5 Servicing Fuel Fitting
Fig. 4 Fuel Line Clamp
14 - 50 FUEL SYSTEMS Ä
Page 1820 of 2438
(3) Ensure the injector holes are clean and all plugs
have been removed. (4) Lubricate the injector O-rings with a drop of
clean engine oil to ease installation. (5) Install the injector assembly into their holes.
Install mounting screws. Fuel rail assembly must be
drawn into the intake manifold evenly making sure
each injector enters its own hole. Once all injectors are
seated, tighten bolts to 23 N Im (200 in. lbs) torque.
(6) Connect vacuum hose to fuel pressure regulator.
(7) Close fuel tube clip around fuel tubes and install
fastener. (8) Lubricate the ends of the chassis fuel tubes with
a light coating of clean 30 weight engine oil. Connect
fuel supply and return hoses to chassis fuel tube
assembly. Pull back on the quick connect fittings to
ensure complete insertion. Refer to Quick Connect
Fittings in the Fuel Delivery section of this group. (9) Connect vacuum hose intake manifold nipple.
(10) Connect negative cable to battery.
CAUTION: When using the ASD Fuel System Test, the
Auto Shutdown (ASD) Relay remains energized for
either 7 minutes, until the test is stopped, or until the
ignition switch is turned to the Off position.
(11) With the DRBII scan tool, use the ASD Fuel
System Test to pressurize system and check for leaks.
FUEL INJECTOR
The fuel rail must be removed to service the injec-
tors. Refer to Fuel Injector Rail Assembly in this
section.
REMOVAL
WARNING: RELEASE FUEL SYSTEM PRESSURE BE-
FORE SERVICING FUEL SYSTEM COMPONENTS.
WHEN SERVICING FLEXIBLE FUEL VEHICLES,
WEAR METHANOL RESISTANT GLOVES AND EYE
PROTECTION AND AVOID BREATHING FUMES. DO NOT ALLOW METHANOL/GASOLINE MIXTURES TO
CONTACT SKIN. SERVICE VEHICLES IN WELL VEN-
TILATED AREAS AND AVOID IGNITION SOURCES.
NEVER SMOKE WHILE SERVICING THE VEHICLE.
(1) Disconnect electrical connector from injector
(Fig. 8).
(2) Position fuel rail assembly so that the fuel injec-
tors are easily accessible (Fig. 9). (3) Remove injector lock ring from fuel rail and
injector. Pull injector straight out of fuel rail receiver
cup. (4) Check injector O-ring for damage. Replace dam-
aged O-rings. If injector is reused, install a protective
cap on the injector tip to prevent damage. (5) Repeat steps for remaining injectors.
INSTALLATION
WARNING: FUEL INJECTORS AND INJECTOR
O-RINGS DESIGNED FOR GASOLINE ONLY VE-
HICLES CANNOT BE USED ON FLEXIBLE FUEL AA-
BODY VEHICLES. WHEN SERVICING THE FUEL SYS-
TEM OF A FLEXIBLE FUEL VEHICLE, ONLY USE
ORIGINAL EQUIPMENT OR EQUIVALENT REPLACE-
MENT COMPONENTS.
Fig. 7 Fuel Injector Ports
Fig. 8 Servicing Fuel Injectors
14 - 80 FUEL SYSTEMS Ä
Page 1850 of 2438
(8) Cover or plug the injector ports with while ser-
vicing the injectors (Fig. 9).
INSTALLATION
(1) Ensure the injectors are seated into the re-
ceiver cup, with the lock ring in place. (2) Ensure the injector wiring connectors are fully
inserted into the fuel injectors. (3) Make sure the injector holes are clean and all
plugs have been removed (Fig. 9). (4) Lubricate the injector O-rings with a drop of
clean engine oil. (5) Install the injector assemblies into their holes
and install the attaching bolts. Draw the fuel rail as-
sembly evenly into the intake manifold, making sure
each injector enters its own hole. The oil separator
bracket must be on top of the fuel rail bracket (Fig.
8). (6) Once all injectors are evenly seated, tighten the
fuel rail attaching bolts to 23 N Im (200 in. lbs.)
torque. (7) Connect the fuel injector wiring harness to the
main harness. (8) Lubricate the ends of the chassis tubes with
clean 30 weight engine oil. (9) Connect fuel hose quick connect fittings to the
chassis fuel tubes. Pull on the fittings to ensure com-
plete connection. Refer to Quick Connect Fittings in the Fuel Deliv-
ery Section of this group. (10) Connect the vacuum hose to the fuel pressure
regulator. (11) Connect negative cable to battery.
CAUTION: When using the ASD Fuel System Test,
the Auto Shutdown (ASD) Relay remains energized
for either 7 minutes, until the test is stopped, or un-
til the ignition switch is turned to the Off position. (12) With the DRBII scan tool the ASD Fuel Sys-
tem Test to pressurize the fuel system to check for
leaks.
FUEL INJECTORS
Remove the fuel rail to service the injectors. Refer
to Fuel Injector Rail Assembly in this section.
REMOVAL
(1) Disconnect injector electrical connector from in-
jector. (Fig. 10).
(2) Position fuel rail assembly so that the fuel in-
jectors are easily accessible (Fig. 11).
(3) Remove injector lock ring off the fuel rail and
injector. Pull injector straight out of fuel rail receiver
cup (Fig. 11). (4) Check injector O-ring for damage. If O-ring is
damaged, it must be replaced. If injector is reused, a
protective cap must be installed on the injector tip to
prevent damage. (5) Repeat for remaining injectors.
Fig. 9 Fuel Injector Ports
Fig. 10 Fuel Rail and Injector Assembly
Fig. 11 Servicing Fuel Injectors
14 - 110 FUEL SYSTEMS Ä
Page 1882 of 2438
(3) Loosen fuel return hose clamp and remove fuel
return hose from nipple. (4) Remove vacuum hose from fuel pressure regu-
lator. (Fig. 13). (5) Remove screw holding fuel return tube to the
intake manifold. (6) Remove fuel pressure regulator screws. Remove
fuel pressure regulator from engine.
INSTALLATION
(1) Lubricate O-ring on fuel pressure regulator
with clean 30 weight engine oil. (2) Install fuel pressure regulator into fuel rail.
Tighten screws to 10 N Im (90 in. lbs.) torque.
(3) Install screw holding fuel return tube clamp in
place. Tighten screw to 10 N Im (95 in. lbs.) torque.
(4) Connect vacuum hose to fuel pressure regula-
tor. (5) Connect fuel return hose to fuel return tube.
Tighten hose clamp to 1 N Im (10 in. lbs.) torque.
(6) Connect negative battery cable.
CAUTION: When using the ASD Fuel System Test,
the Auto Shutdown (ASD) Relay remains energized
for either 7 minutes, until the test is stopped, or un-
til the ignition switch is turned to the Off position.
(7) With the ignition key in ON position, access
the DRBII scan tool's ASD Fuel System Test to pres-
surize the fuel system. Check for leaks.
FUEL INJECTORS
WARNING: THE 3.0L MPI FUEL SYSTEM IS UNDER
A CONSTANT PRESSURE OF APPROXIMATELY 330
KPA (48 PSI). PERFORM FUEL PRESSURE RE-
LEASE PROCEDURE BEFORE SERVICING THE
FUEL INJECTORS.
REMOVAL
(1) Perform the Fuel Pressure Release Procedure.
(2) Disconnect negative cable from battery.
The fuel rail must be removed first to service the
injectors. Refer to Fuel Injector Rail Assembly Re-
moval in this section. (3) Label each injector connector with its cylinder
number. Disconnect electrical connector from injec-
tor. (4) Position fuel rail assembly so that the fuel in-
jectors are easily accessible. (5) Remove injector clip from fuel rail and injector
(Fig. 14).
(6) Pull injector straight out of fuel rail receiver
cup (Fig. 15).
Fig. 13 Fuel Pressure Regulator
Fig. 14 Fuel Injector and Rail
Fig. 15 Servicing Fuel Injector
14 - 142 FUEL SYSTEMS Ä
Page 2008 of 2438
GOVERNOR
To service the governor assembly in the vehicle, it
is not necessary to remove the transfer gear cover,
transfer gear, and governor support. The governor
may be serviced by removing the transaxle oil pan
and valve body assembly. With the oil pan and valve
body removed, the governor may be unbolted from
the governor support and removed. When cleaning or assembling the governor, make
sure the governor valves move freely in the bores of
the governor body.
ALUMINUM THREAD REPAIR
Damaged or worn threads in the aluminum tran-
saxle case and valve body can be repaired by the use
of Heli-Coils, or equivalent. This repair consists of
drilling out the worn-out damaged threads. Then tap-
ping the hole with a Heli-Coil tap, or equivalent, and
installing a Heli-Coil insert, or equivalent, into the
hole. This brings the hole back to its original thread
size. Heli-Coil, or equivalent, tools and inserts are
readily available from most automotive parts suppli-
ers.
OIL COOLERS AND TUBES REVERSE FLUSHING
When a transaxle failure has contaminated the
fluid, the oil cooler(s) must be flushed. The torque
converter must be replaced with an exchange unit.
This will insure that metal particles or sludged oil
are not transferred back into the reconditioned (or
replaced) transaxle.
CAUTION: If vehicle is equipped with two oil cool-
ers (one in the radiator tank, one in front of the ra-
diator) they must be flushed separately. Do not
attempt to flush both coolers at one time.
(1) Disconnect the cooler lines at the transmission.
(2) Using a hand suction gun filled with mineral
spirits, reverse flush the cooler. Force mineral spirits
into the From Cooler line of the cooler (Fig. 9) and
catch the exiting spirits from the To Coolerline.
Observe for the presence of debris in the exiting
fluid. Continue until fluid exiting is clear and free
from debris. (3) Using compressed air in intermittent spurts,
blow any remaining mineral spirits from the cooler,
again in the reverse direction. (4) To remove any remaining mineral spirits from
the cooler, one (1) quart of automatic transmission
fluid should be pumped through the cooler before re-
connecting. (5) If at any stage of the cleaning process, the
cooler does not freely pass fluid, the cooler must be
replaced.
OIL COOLER FLOW CHECK
After the new or repaired transmission has been
installed and filled to the proper level with auto-
matic transmission fluid. The flow should be checked
using the following procedure: (1) Disconnect the From coolerline at the trans-
mission and place a collecting container under the
disconnected line. (2) Run the engine at curb idle speed , with the
shift selector in neutral. (3) If the fluid flow is intermittent or it takes more
than 20 seconds to collect one quart of automatic
transmission fluid, the cooler should be replaced.
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.
(4) If flow is found to be within acceptable limits,
reconnect the cooler line. Then fill transmission to
the proper level, using the approved type of auto-
matic transmission fluid.
TRANSAXLE AND TORQUE CONVERTER REMOVAL
Transaxle removal does NOT require engine
removal. (1) The transaxle and torque converter must be re-
moved as an assembly; otherwise, the torque con-
verter drive plate, pump bushing, or oil seal may be
damaged. The drive plate will not support a load;
therefore, none of the weight of the transaxle should
be allowed to rest on the plate during removal. (2) Disconnect battery negative cable .
(3) Disconnect throttle linkage and shift linkage
from transaxle.
Fig. 9 Cooler Line Identification
21 - 48 TRANSAXLE Ä
Page 2059 of 2438
CAUTION: If the vehicle is equipped with two oil
coolers (one in the radiator tank, one in front of the
radiator) they must be flushed separately. Do not
attempt to flush both coolers at one time. (1) Disconnect the cooler lines at the transmission.
(2) Using a hand suction gun filled with mineral
spirits, reverse flush the cooler. Force mineral spirits
into the From Cooler line of the cooler (Fig. 7) and
catch the exiting spirits from the To Coolerline.
Observe for the presence of debris in the exiting
fluid. Continue until fluid exiting is clear and free
from debris.
(3) Using compressed air in intermittent spurts,
blow any remaining mineral spirits from the cooler,
again in the reverse direction. (4) To remove any remaining mineral spirits from
the cooler, one (1) quart of automatic transmission
fluid should be pumped through the cooler before re-
connecting. (5) If at any stage of the cleaning process, the
cooler does not freely pass fluid, the cooler must be
replaced.
OIL COOLER FLOW CHECK
After the new or repaired transmission has been
installed, filled to the proper level with automatic
transmission fluid. The flow should be checked using
the following procedure: (1) Disconnect the From coolerline at the trans-
mission and place a collecting container under the
disconnected line. (2) Run the engine at curb idle speed , with the
shift selector in neutral. (3) If the fluid flow is intermittent or it takes more
than 20 seconds to collect one quart of automatic
transmission fluid, the cooler should be replaced. 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.
(4) If flow is found to be within acceptable limits,
reconnect the cooler line. Then fill transmission to
the proper level, using the approved type of auto-
matic transmission fluid.
TRANSAXLE REMOVAL AND INSTALLATION
Transaxle removal does NOT require engine re-
moval. See Group 7-Cooling, to drain engine cooling sys-
tem and remove coolant return extension (3.0 liter
engine only). (1) The transaxle and torque converter must be re-
moved as an assembly; otherwise, the torque con-
verter drive plate, pump bushing or oil seal may be
damaged. The drive plate will not support a load;
therefore, none of the weight of the transaxle should
be allowed to rest on the drive plate during removal. (2) Disconnect negative battery cable.
(3) Disconnect transaxle shift linkage.
(4) Install engine support fixture and support en-
gine (Fig.1).
(5) Remove upper bell housing upper bolts.
(6) Raise vehicle. Remove front wheels. Refer to
Suspension, Group 2 to remove wheel hub nut and
both drive shafts. (7) Remove left plastic splash to gain access to the
transaxle (Fig. 2). (8) Remove torque converter dust shield to gain ac-
cess to torque converter bolts (Fig. 3). (9) Mark torque converter and drive plate with
chalk, for reassembly. Remove torque converter
mounting bolts. (10) Disconnect electrical connectors at transmis-
sion range switch and Park/Neutral Position Switch
(Fig. 4).
Fig. 7 Cooler Line Location
Fig. 1 Engine Support Fixture (Typical)
Ä TRANSAXLE 21 - 99
Page 2154 of 2438
WHEELS SERVICE PROCEDURES INDEX
page page
General Information ........................ 6
Tire and Wheel Balance .................... 6
Tire and Wheel Run Out .................... 7 Wheel Installation
......................... 6
Wheel Replacement ....................... 6
GENERAL INFORMATION
Original equipment wheels are designed for proper
operation at all loads up to the maximum vehicle ca-
pacity. All models use steel or cast aluminum drop center
wheels. The safety rim wheel (Fig. 1) has raised sec-
tions between the rim flanges and the rim well A.
Initial inflation of the tires forces the bead over
these raised sections. In case of tire failure the raised
sections help 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 and alignment equipment.
WHEEL INSTALLATION
The wheel studs and nuts are designed for specific
applications and must be replaced with equivalent
parts. Do not use replacement parts of lessor quality
or a substitute design. All aluminum and some steel
wheels have wheel stud nuts which feature an en-
larged nose. This enlarged nose is necessary to en-
sure proper retention of the aluminum wheels. Before installing the wheel, be sure to remove any
build up of corrosion on the wheel mounting surfaces
with scraping and wire brushing. Installing wheels
without good metal-to-metal contact could cause later
loosening of wheel nuts. This could adversely affect
the safety and handling of your vehicle. To install the wheel, position it properly on the
mounting surface using the hub pilot as a guide. All wheel nuts should be lightly tightened before progres-
sively tightening them in sequence (Fig. 2). Tighten
wheel nuts to 129 N Im (95 ft. lbs.). Never use oil or
grease on studs or nuts.
WHEEL REPLACEMENT
Wheels must be replaced if they:
² have excessive run out
² are bent or dented
² leak air through welds
² have damaged bolt holes
Wheel repairs employing hammering, heating, or
welding are not allowed. Original equipment replacement wheels are avail-
able through your dealer. When obtaining wheels from
any other source, the replacement wheels should be
equivalent in load carrying capacity. The wheel dimen-
sions (diameter, width, offset, and mounting configura-
tion) must match original equipment wheels. Failure to
use equivalent replacement wheels may adversely af-
fect the safety and handling of your vehicle. Replace-
ment with used wheels is not recommended as
their service history may have included severe
treatment or very high mileage and they could
fail without warning.
TIRE AND WHEEL BALANCE
Balancing need is indicated by vibration of seats,
floor pan, or steering wheel when driving over 90 km/h
(55 mph) on a smooth road.
Fig. 1 Safety Rim
Fig. 2 Tightening Wheel Nuts (5-Stud)
22 - 6 WHEELSÐTIRES Ä
Page 2155 of 2438
It is recommended that a two plane dynamic bal-
ancing machine be used when a wheel and tire as-
sembly require balancing. Static balancing should be
used only when a two plane dynamic balancing is not
available. For static imbalance, find location of heavy spot
causing imbalance and counterbalance wheel directly
opposite the heavy spot. Determine weight required
to counterbalance the area of imbalance. Place half
of this weight on the inner rim flange. Then place
the other half on the outer rim flange (Fig. 3). Off-
vehicle balancing is preferred.
TIRE AND WHEEL RUN OUT
Radial run out is the difference between the high
and low points on the tire or wheel periphery. Lateral run out is the wobble of the tire or wheel.
Radial run out of more than 1.5 mm (.060 inch)
measured at the center line of the tread may cause
the vehicle to shake. Lateral run out of more than 2.0 mm (.080 inch)
measured near the shoulder of the tire may cause the
vehicle to shake. Sometimes radial run out can be reduced by relo-
cating the wheel and tire assembly on the mounting
studs (See Method 1). If this does not reduce run out
to an acceptable level, the tire can be rotated on the
wheel. (See Method 2).
METHOD 1 (RELOCATE WHEEL ON HUB)
Check accuracy of the wheel mounting surface;ad-
just wheel bearings. Drive vehicle a short distance to eliminate tire flat
spotting from a parked position. Make sure all wheel nuts are properly torqued
(Fig. 2). Use run out gauge D-128-TR to determine run out
(Fig. 4).
Relocate wheel on the mounting, two studs over
from the original position. Retighten wheel nuts (Fig. 2) until all are properly
torqued, to eliminate brake distortion. Check radial run out. If still excessive, mark tire
sidewall, wheel, and stud at point of maximum run
out (Fig. 5), and proceed to Method #2.
METHOD 2 (RELOCATE TIRE ON WHEEL)
Rotating tire on wheel is particularly effective
when there is run out in both tire and wheel. Remove tire from wheel and remount wheel on hub
in former position. Check wheel radial run out (Fig. 6). It should be no
more than 0.9 mm (.035 inch). Lateral run out (Fig. 6) should be no more than 1.1
mm (.045 inch). If point of greatest wheel radial run out is near
original chalk mark, remount tire 180 degrees from
its original position. Recheck run out.
Fig. 3 Counterbalancing
Fig. 4 Run out Gauge D-128-TR
Fig. 5 Chalk Marking on Wheel, Tire, and Stud
Ä WHEELSÐTIRES 22 - 7