Troubleshooting

Troubleshooting

Vehicle Inspection

SYMPTOM CHART

Symptom	Suspect area	Remedy (Refer to page)
Squeak or grunt noise from front suspension, more likely to occur in cold weather or on rough roads or when turning.	Front Stabilizer Bar	Under these conditions, the noise is acceptable.
Knock noise from front suspension, occurs when turning and when not turning.	Loose front struts or shock absorbers.	Check for loose nuts or bolts. Tighten to specification.
Knock noise from rear suspension, occurs when shifting from reverse to drive.	Loose or Damaged Rear Suspension Components	Inspect rear suspension components for looseness or damage. Repair or install new components as necessary.
Click or pop noise from front suspension, more noticeable on rough roads or bumps.	Worn or damaged ball joints.	Install a new lower arm as necessary.
Click or pop noise occurs when turning the vehicle.	Worn or damaged ball joints.	Install a new lower arm as necessary.
Click or clunk noise occurs when accelerating while turning.	Damaged or worn Birfield joint.	Repair or install a new Birfield joint as necessary. Refer to Group DS - Propeller Shaft.
Front suspension noise - squeak, creak or rattle - mainly occurs on bumps or rough roads.	Steering components Loose or bent front struts or shock absorbers Damaged spring or spring seats Worn or damaged arm bushings Worn or damaged stabilizer bar bushings or links	Go to Diagnostic Procedure A.
Squeak or scrape - front strut noise occurring on rough roads or when turning the vehicle.	Uneven seating surface between strut insulator and body panel, burrs around strut insulator bolts and insulator bolt mounting holes	Repair or install new parts as necessary.
Rear suspension noise - squeak, creak or rattle - mainly occurs on bumps or rough roads.	Loose or bent rear shock absorbers Damaged spring or spring seats Worn or damaged suspension arm bushings	Go to Diagnostic Procedure B.
Shudder - occurs during acceleration from low speed or when stopping.	Rear axle assembly incorrectly positioned Damaged or worn front suspension components	Inspect axle mounts and rear suspension for damage or wear. Repair as necessary. Check for loose stabilizer bar, damaged or loose strut/strut bushings, or loose or worn ball joints. Inspect tie rod for wear or damage. Repair or install new components as necessary.
Shimmy - most noticeable during coasting/deceleration - also stiff steering.	Excessive Positive Caster	Check wheel alignment angles. Adjust as necessary.
Tire noise - hum/moan at constant speed.	Abnormal wear	Rotate the tire and check tire wear. Install a new tire as necessary. Inspect suspension components for damage or wear. Perform wheel alignment.
Tire noise - noise tone decreases as vehicle speed decreases.	Unbalanced tire	Balance the tire and road test. Install a new tire as necessary.
Tire noise - ticking, changes with speed.	Nail puncture or stone in tire tread	Inspect the tire. Repair or replace as necessary.
Wheel and tire - vibration and noise directly related to vehicle speed, independent of acceleration, coasting or deceleration.	Damaged or worn tire	Go to Diagnostic Procedure C.
Tire shake or shimmy - occurs at lower speeds.	Damaged wheel bearings	Rotate the wheel and check for abnormal play or roughness in the wheel bearing. If necessary, adjust or install new wheel bearings. Refer to Group DS - Front/Rear Axle.
	Damaged wheel	Inspect the wheel for damage. If necessary, install a new wheel.
	Damaged or worn suspension components	Inspect the suspension components for wear or damage. Repair as necessary.
	Loose wheel nuts	Check the wheel nuts. Tighten to specification.
	Damaged or uneven tire wear	Rotate the tire and check for abnormal wear or damage. If necessary, install a new tire.
Tire shimmy or vibration - occurs at low speeds	Wheel/tire out of balance
	Uneven tire wear	Check the tires for abnormal wear. If necessary, install a new tire.
	Excessive radial runout of wheel or tire	Perform a radial runout test on the wheel and tire. If necessary, install a new tire.
	Worn or damaged wheel studs or elongated stud holes	Inspect the wheel studs and wheels. If necessary, install new components.
	Excessive lateral runout of wheel or tire	Perform a lateral runout test on the wheel and tire. Inspect the wheel, tire and hub. If necessary, repair or install new components.
	Foreign material between brake disc and hub.	Clean the mounting surfaces of the brake disc and hub. Refer to Group DS - Front/Rear Axle.
Shake or shudder at high speed - occurs at high speeds.	Excessive wheel hub runout Damaged or worn tires Damaged or worn wheel bearings Worn or damaged suspension or steering linkage Brake disc or drum imbalance	Go to Detailed Test D.
Drift left or right	Tires Steering linkage Alignment Base brake system	Go to Detailed Test E.
Steering Wheel	Alignment Steering linkage Front lower arm ball joint	Go to Detailed Test F.
Tracks incorrectly	Rear suspension Caster	Go to Detailed Test G.
Harsh ride	Front strut and spring assembly Rear shock absorber and spring assembly	Go to Detailed Test H.
Excessive Noise	Front or rear stabilizer bar components Springs Suspension components Shock absorbers	Go to Detailed Test I.
Abnormal tire wear	Tire or unbalanced wheels Tire inflation Strut Alignment	Go to Detailed Test J.
Vibration	Wheel/tire Front drive axle shaft(s) Steering system Strut and spring assembly Strut and spring mount Front lower arm ball joint Front lower arm bolt bushing Stabilizer bar bushings Wheel hubs and bearings Rear suspension arms and bushings	Go to Detailed Test K.
Vehicle leans	Tire/wheel Vehicle load Suspension components Incorrect ground clearance	Inflate tires to specification. Redistribute load as necessary. Visually inspect the suspension system. If necessary, adjust ride height.
Poor steering return	High steering knuckle torque Alignment	Go to Detailed Test E.

DIAGNOSTIC PROCEDURE A: FRONT SUSPENSION NOISE

CONDITIONS	DETAILS/RESULTS/ACTIONS
A1. VEHICLE ROAD TEST
	1 Road test the vehicle. 2 During the road test, drive the vehicle over a rough road. Determine the area or component from which the noise originates. Is a knocking, creaking, or clunking noise heard? > YES: Go to A2. > NO: The suspension system is normal. Diagnose other suspected systems.
A2. CHECK STEERING SYSTEM
	Inspect the steering system for wear or damage. Perform the steering linkage inspection. Inspect the tire wear pattern. Are the steering components worn or damaged? > YES: Repair the steering system. Install new components as necessary. Verify normal operation of the system. > NO: Go to A3.
A3. CHECK FRONT SHOCK ABSORBER/STRUT
	1 Check the front shock absorber/strut mounts for loose bolts or nuts. 2 Inspect the front shock absorbers/struts for damage. Perform the shock absorber inspection. Are the front shock absorbers/struts loose or damaged? > YES: Tighten to specification if loose. Install new front shock absorbers/struts if damaged. Verify normal operation of the system. > NO: Go to A4.
A4. CHECK FRONT SPRINGS
	Inspect the front coil springs and front spring seats/brackets for wear or damage. Are the front coil springs or spring seats/brackets worn or damaged? > YES Repair or install new components as necessary. Verify normal operation of the system. > NO Go to A5.
A5. CHECK STABILIZER BAR
	1 Inspect the stabilizer bar bushings and links for damage or wear. 2 Inspect the stabilizer bar for damage. 3 Inspect the stabilizer bar brackets for looseness or damage. Are the stabilizer bar/crossmember components loose, worn, or damaged? > YES: Repair or install new components as necessary. Verify normal operation of the system. > NO: The suspension system is normal. Diagnose other suspected systems.

DIAGNOSTIC PROCEDURE B: REAR SUSPENSION NOISE

CONDITIONS	DETAILS/RESULTS/ACTIONS
B1. VEHICLE ROAD TEST
	1 Road test the vehicle. 2 During the road test, drive the vehicle over a rough road. Determine the area or component from which the noise originates. Is a knocking, creaking, or clunking noise heard? > YES: Go to B2. > NO: The suspension system is normal. Diagnose other suspected systems.
B2. CHECK REAR SHOCK ABSORBER/STRUT
	1 Raise and support the vehicle. Refer to Group GI - Jacking Points. 2 Check the rear shock absorber/strut mounts for loose bolts or nuts. 3 Inspect the rear shock absorbers/struts for damage. Perform the shock absorber inspection. Are the rear shock absorbers/strut loose or damaged? > YES: Tighten to specification if loose. Install new rear shock absorbers/struts if damaged. Verify normal operation of the system. > NO: Go to B3.
B3. CHECK REAR COIL SPRINGS
	Inspect the rear coil springs and rear spring seats/brackets for wear or damage. Are the rear coil springs or spring seats/brackets worn or damaged? > YES Repair or install new components as necessary. Verify normal operation of the system. > NO Go to B4.
B4. CHECK TRAILING ARMS
	1 Inspect the trailing arm bushings for wear or damage. Check the trailing arm bolts for looseness. 2 Inspect the trailing arms for twisting or bending. Are the trailing arms loose, damaged, or worn? > YES: Repair or install new components as necessary. Verify normal operation of the system. > NO: The suspension system is normal. Diagnose other suspected systems.

DIAGNOSTIC PROCEDURE C: WHEEL AND TIRE

CONDITIONS	DETAILS/RESULTS/ACTIONS
C1. ROAD TEST VEHICLE
	Wheel or tire vibration felt through the steering wheel is most likely related to the front wheel or tire. Vibration felt through the seats is most likely related to the rear wheel or tire. This is not always true, but it can help isolate the problem to the front or rear of the vehicle. Road test the vehicle at various speed ranges. During the road test, if the vibration can be eliminated by shifting the vehicle into neutral or if the vibration depends on engine speed, the cause is not the wheels or tires. Is there vibration and noise? > YES Go to C2. > NO The wheel and tire are normal. Diagnose other suspected systems.
C2. CHECK FRONT WHEEL BEARINGS
	Inspect the front wheel hub bearings. Refer to "Wheel Bearing Inspection" (see group DS - Front Axle). Are the wheel hub bearings normal? > YES Go to C3. > NO Inspect the wheel bearings. Adjust or repair as necessary. Verify normal operation of the system.
C3. CHECK TIRES
	1 Check the tires for loads. 2 Check the wheels for damage. 3 Inspect the tire wear pattern. Does the tire show abnormal wear? > YES: Correct the condition that caused the abnormal wear. Install new tire(s). Verify normal operation of the system. > NO: Go to C4.
C4. TIRE ROTATION DIAGNOSIS
	1 Slowly rotate the tires and watch for signs of lateral runout. 2 Slowly rotate the tires and check for signs of radial runout. Is there visible runout? > YES: Go to C5. > NO: Check wheel and tire balance. Correct as necessary. Verify normal operation of the system.
C5. CHECK TIRE RADIAL RUNOUT
	Measure the radial runout of the wheel and tire assembly. The typical total radial runout specification is 1.15 mm (0.059 in.). Does the radial runout meet specification? > YES Go to C8. > NO Go to C6.
C6. CHECK WHEEL RADIAL RUNOUT
	Measure the wheel radial runout. The typical total radial runout specification is 1.14 mm (0.045 inch). ? Does the radial runout meet specification? > YES Install a new tire. Verify system operation. > NO Go to C7.
C7. CHECK HUB/BRAKE DISC OR DRUM RUNOUT OR STUD CIRCLE RUNOUT
	Measure the pilot or bolt circle runout. Typical runout specifications: ? Pilot runout - less than 0.15 mm (0.006 inch) ? Bolt circle runout - less than 0.38 mm (0.015 inch) ? Does the radial runout meet specification? > YES Install a new wheel. Verify system operation. > NO Repair or install new components as necessary.
C8. CHECK TIRE LATERAL RUNOUT
	Measure the lateral runout of the wheel and tire assembly. The typical total lateral runout specification is 2.5 mm (0.098 inch). ? Does the lateral runout meet specification? > YES The wheel and tire are good. Diagnose other suspect systems. > NO Go to C9.
C9. CHECK WHEEL LATERAL RUNOUT
	Measure the lateral runout of the wheel. The typical total lateral runout specification is 1.2 mm (0.047 inch). ? Does the lateral runout meet specification? > YES Install a new tire. Verify system operation. > NO Go to C10.
C10. CHECK FLANGE FACE LATERAL RUNOUT
	Measure the lateral runout of the flange face. Typical lateral runout specification: ? Hub/brake disc - less than 0.13 mm (0.005 inch) ? Does the lateral runout meet specification? > YES Install a new wheel. Verify system operation. > NO Repair or install new components as necessary.

DIAGNOSTIC PROCEDURE D:

CONDITIONS	DETAILS/RESULTS/ACTIONS
D1. CHECK FRONT WHEEL BEARING ROUGHNESS
	1 Raise and support the front of the vehicle so the front wheel and tire assembly can spin freely. Refer to Group GI - Jack Lifting Points. 2 Rotate the front wheels by hand. ? Do the wheel hub bearings feel rough? > YES Inspect the wheel bearings. Repair as necessary. Verify system operation. > NO Go to D2.
D2. CHECK FRONT WHEEL BEARING END PLAY
	Check the front wheel bearing end play. ? Is the end play within specification? > YES Go to D3. > NO Adjust or repair as necessary. Verify system operation.
D3. MEASURE FRONT WHEEL LATERAL AND RADIAL RUNOUT
	Measure the lateral runout and radial runout of the vehicle front wheels. Go to detailed test C. ? Do the measurements meet specification? > YES Go to D4. > NO Install new wheels and balance the assembly as necessary. Verify system operation.
D4. MEASURE FRONT WHEEL LATERAL RUNOUT
	Measure the lateral runout of the vehicle front tires. Go to detailed test C. ? Is the runout within specification? > YES Go to D5. > NO Install new tires and balance the assembly as necessary. Verify system operation.
D5. MEASURE FRONT WHEEL RADIAL RUNOUT
	Measure the radial runout of the vehicle front tires. Go to detailed test C. ? Is the runout within specification? > YES Balance the front wheel and tire assembly. If any tire cannot be balanced, install a new tire. Verify system operation. > NO Go to D6.
D6. MATCH TIRE AND WHEEL ASSEMBLY
	Mark the high point of runout on the tire and on the wheel. Lower the assembly and rotate the tire 180 degrees (half turn) on the wheel. Inflate the tire and measure the radial runout. ? Is the runout within specification? > YES Balance the assembly. Verify system operation. > NO If the high point is not within 101.6 mm (4 inches) of the first high point on the tire, go to D7.
D7. MEASURE WHEEL FLANGE RUNOUT
	Remove the tire and mount the wheel on a balancing stand. Measure the runout on both wheel flanges. Go to detailed test C. ? Is the runout within specification? > YES Locate and mark the low point on the wheel. Install the tire with the high point of the tire matched to the low point of the wheel. Balance the assembly. Verify system operation. If the condition persists, go to D8. > NO Install a new wheel. Check the runout on the new wheel. If the new wheel is within limits, locate and mark the low point. Install the tire with the high point of the tire matched to the low point of the wheel. Balance the assembly. Verify system operation. If the condition persists, go to D8.
D8. CHECK FOR VIBRATION FROM THE FRONT OF THE VEHICLE
	Rotate the front wheel and tire assembly on a balancing machine while the vehicle is raised on a lift. Feel for vibration in the front fender or while seated in the vehicle. ? Is vibration present? > YES Replace known good wheel and tire assemblies as necessary. Verify system operation. > NO Check the driveline components. Verify system operation.

DIAGNOSTIC PROCEDURE E: PULL TO LEFT OR RIGHT

CONDITIONS	DETAILS/RESULTS/ACTIONS
E1. CHECK THE TIRES
	Inspect the tires for excessive wear or damage. ? Are the tires excessively worn or damaged? > YES Install new tires. > NO Go to E2.
E2. CHECK THE STEERING LINKAGE
	1 Raise and support the vehicle. 2 Inspect the steering components for signs of excessive wear or damage. Refer to Group ST - Specifications. ? Are there signs of excessive wear or damage? > YES Repair or install new components as necessary. > NO Go to E3.
E3. CHECK VEHICLE ALIGNMENT
	Position the vehicle on an alignment rack. Check the vehicle alignment. ? Does the alignment meet specification? > YES Go to E4. > NO Adjust the alignment as necessary.
E4. BRAKE DIAGNOSIS
	Apply the brakes while driving. ? Does the vehicle pull or grab during braking? > YES Refer to Group BR - Specifications. > NO If the steering wheel is centered, the vehicle is operating correctly. If the steering wheel is off-center, go to detailed test F.

DIAGNOSTIC PROCEDURE F: STEERING WHEEL OFF CENTER

CONDITIONS	DETAILS/RESULTS/ACTIONS
F1. CHECK FOR CLEAR VISION
	Position the vehicle on an alignment rack. ? Does the caster meet specification? > YES Go to F2. > NO Adjust the caster to specification.
F2. CHECK STEERING COMPONENTS
	1 Raise and support the vehicle. 2 Inspect the steering components for excessive wear or damage. Refer to Group ST - Specifications. ? Are the steering components excessively worn or damaged? > YES Repair or replace as necessary. > NO If the vehicle tracks correctly, the vehicle is OK. If the vehicle does not track correctly, go to Detailed Test.

DIAGNOSTIC PROCEDURE G: INCORRECT TRACKING

CONDITIONS	DETAILS/RESULTS/ACTIONS
G1. CHECK THE ROLLER
	Install the vehicle on an alignment rack. ? Does the roll meet specification? > YES Go to G2. > NO Replace bent or damaged components.
G2. CHECK THE REAR SUSPENSION
	1 Measure the wheelbase of the vehicle on the left and right sides. 2 Compare the measurements. ? Are the measurements the same? > YES If the ride is smooth, the vehicle is OK. If the ride is rough, go to Detailed Test. > NO Inspect the rear suspension components for wear or damage. Repair or replace as necessary.

DIAGNOSTIC PROCEDURE H: HARSH RIDE

CONDITIONS	DETAILS/RESULTS/ACTIONS
H1. CHECK THE FRONT SHOCK ABSORBER
	1 Raise the vehicle on a hoist. 2 Inspect the front shock absorber for oil leaks or damage. ? Are the tires excessively worn or damaged? > YES Install new front shock absorbers. > NO Go to H2.
H2. CHECK THE REAR SHOCK ABSORBERS
	Inspect the rear shock absorbers for oil leaks or damage. ? Are the rear shock absorbers leaking? > YES Install new rear shock absorbers. > NO The vehicle is OK. Go to Symptom Troubleshooting.

DIAGNOSTIC PROCEDURE I: EXCESSIVE NOISE

CONDITIONS	DETAILS/RESULTS/ACTIONS
I1. CHECK THE SUSPENSION
	1 Raise and support the vehicle. 2 Inspect the shock absorber mounting bolts. ? Are the mounting bolts loose or broken? > YES Tighten or install new shock absorber mounting bolts. > NO Go to I2.
I2. CHECK THE COIL SPRING AND TORSION BARS
	Inspect the springs and stabilizer bars for damage. ? Is a spring or stabilizer bar damaged? > YES Install new springs and/or stabilizer bars. > NO Go to I3.
I3. CHECK FRONT SUSPENSION
	Inspect the front suspension components for excessive wear or damage. ? Are the front suspension components worn or damaged? > YES Install new front suspension components. > NO The vehicle is OK. Go to Symptom Troubleshooting.

DIAGNOSTIC PROCEDURE J: ABNORMAL TIRE WEAR

CONDITIONS	DETAILS/RESULTS/ACTIONS
J1. CHECK TIRES
	1 Raise and support the vehicle. 2 Inspect the tires for uneven wear on the inner or outer shoulder. ? Is there uneven tire wear? > YES Align the vehicle. Install new tires if excessively worn. > NO Go to J2.
J2. UNEVEN TIRE WEAR
	Inspect the tires for feathering. ? Do the tires have a feathered pattern? > YES Align the vehicle. Install new tires if excessively worn. > NO Go to J3.
J3. CHECK FOR CUPPED TIRES
	Inspect the tires for cupping or bulging. ? Are the tires cupped or bulging? > YES Balance and rotate the tires. > NO The vehicle is OK. Go to Symptom Troubleshooting.

DIAGNOSTIC PROCEDURE K: VIBRATION

CONDITIONS	DETAILS/RESULTS/ACTIONS
K1. ROAD TEST
	Drive the vehicle at the speed at which the customer reported the vibration. ? Is the vibration present? > YES Go to K2. > NO The vehicle is OK. Go to Symptom Troubleshooting.
K2. CHECK TIRES
	1 Raise and support the vehicle using a frame contact hoist. 2 Inspect the tires for excessive wear or damage, cupping, or flat spots. ? Are the tires OK? > YES Go to K3. > NO Inspect the suspension components for misalignment, abnormal wear, or damage that may have contributed to tire wear. Correct the suspension concerns and install new tires.
K3. CHECK WHEEL BEARINGS
	Rotate the tires by hand to check the wheel bearings for roughness. ? Is the front hub bearing OK? > YES Go to K4. > NO Install new front hub bearings as necessary. Refer to Group DS - Front Axle.
K4. TIRE/WHEEL BALANCE
	Check the tire/wheel balance. ? Are the tires balanced? > YES Go to K5. > NO Balance the tires and wheels as necessary.
K5. MEASURE RUNOUT
	For each wheel runout measurement, locate and mark the following points. - High point of tire/wheel assembly total radial runout - High point of wheel radial runout - High point of wheel lateral runout ? Is the runout within specification? > YES Go to Tires/Wheels. > NO Go to K6.
K6. REPLACE WHEELS AND TIRES
	1 Replace with a known good set of wheels and tires. 2 Perform a road test. 3 If the vehicle still shakes or vibrates, note the vehicle speed and/or engine speed at which it occurs. ? Is the vibration felt? > YES Engine/transmission imbalance. Refer to Group TR Specifications, Group EM, Group FL, and Group EC. > NO Install the original tires and wheel assemblies one at a time, testing after each step until the tire(s)/wheel(s) are damaged (if necessary). Check the system for normal operation.

Noise, vibration and harshness problems in the wheels/tires are directly related to vehicle speed and are generally not affected by acceleration, coasting or deceleration. In addition, an unbalanced wheel and tire may vibrate at more than one speed. Vibration affected by engine speed, or eliminated by shifting the transmission to Neutral, is not related to the tire and wheel. Generally, tire and wheel vibrations felt through the steering wheel are related to the front tire and wheel assembly. Vibrations felt in the seat or floor are related to the rear tire and wheel assembly. This may help initially isolate the problem to the front or rear. Pay special attention to the tires and wheels. There are several symptoms that may be caused by a damaged or worn tire and wheel. Perform a careful visual inspection of the tires and wheel assemblies. Slowly rotate the wheels and watch for signs of lateral or radial runout. Refer to the tire wear chart to determine the tire wear conditions and actions.

WHEEL AND TIRE DIAGNOSIS
Rapid Wear in Center	Rapid Wear on Both Shoulders	Wear on One Shoulder
Center of Tread Worn Down to Fabric Due to Excessively Inflated Tires No Rotation Excessive Toe-in on Drive Wheels Sudden Acceleration on Drive	Underinflated Tires Worn Suspension Components Excessive Speed Through Turns No Rotation	Toe Adjustment Not to Specification Camber Out of Specification Damaged Strut Damaged Lower Arm
Partial Wear	Feathered Edge	Wear Pattern
Caused by uneven burrs on brake drums.	Toe Adjustment Not to Specification Damaged or Worn Tie Rod Ends Damaged Joint	Excessive Toe-in on Non-Drive Wheels No Rotation