Noise Conditions
Gear noise is typically a howling or whining due to gear damage or incorrect bearing preload. It can occur at various
speeds and driving conditions, or it can be continuous
Chuckle is a particular rattling noise that sounds like a stick against the spokes of a spinning bicycle wheel. It occurs
while decelerating from approximately 64 km/h (40 miles/h) and can usually be heard all the way to a stop. The
frequency varies with vehicle speed
Knock is very similar to chuckle, though it may be louder and occurs on acceleration or deceleration. The tear down will
disclose what has to be corrected
Check and rule out tires, exhaust and trim items before disassembling the transmission to diagnose and correct gear noise.
The noises described under Road Test usually have specific causes that can be diagnosed by observation as the unit is
disassembled. The initial clues are the type of noise heard on the road test and the driving conditions.
Vibration Conditions
wear. NOTE: New Constant Velocity (CV) joints should not be installed unless disassembly and inspection revealed unusual
Clicking, popping or grinding noises may be caused by the following:
Cut or damaged CV joint boots resulting in inadequate or contaminated lubricant in the outboard or inboard CV joint
bearing housings
Loose CV joint boot clamps
Another component contacting the rear drive half shaft
Worn, damaged or incorrectly installed wheel bearing, suspension or brake component
Vibration at highway speeds may be caused by the following:
Out-of-balance front or rear wheels
Out-of-round tires
Driveline imbalance
Driveline run-out (alignment)
NOTE: Rear drive half shafts are not balanced and are not likely to contribute to rotational vibration disturbance.
Shudder or vibration during acceleration (including from rest) may be caused by the following:
Driveline alignment
Excessively worn or damaged outboard or inboard CV joint bearing housing
Excessively high CV joint operating angles caused by incorrect ride height. Check ride height, verify correct spring rate
and check items under Inoperative Conditions
Excessively worn driveshaft components
Leakage Conditions
1. Inspect the CV joint boots for evidence of cracks, tears or splits.
2. Inspect the underbody for any indication of grease splatter in the vicinity of the rear drive half shaft, outboard and
inboard CV joint boot locations, which is an indication of CV joint boot or CV joint boot clamp damage.
3. Inspect the inboard CV joint bearing housing seal for leakage.
Inoperative Conditions
If a CV joint or rear drive half shaft pull-out occurs, check the following:
suspension components for correct location, damage or wear
bushings for wear
subframe for damage
bent or worn components
- Stabilizer bar link
- Left-hand rear suspension lower arm and bushing
- Right-hand rear suspension lower arm and bushing
- Rear wheel hub and rear drive half shaft
Road Test
A gear-driven unit will produce a certain amount of noise. Some noise is acceptable and may be audible at certain speeds or
under various driving conditions as on a newly paved blacktop road. The slight noise is in no way detrimental and must be
considered normal.
The road test and customer interview (if available) provide information needed to identify the condition and give direction to
the correct starting point for diagnosis.
1. Make notes throughout the diagnosis routine. Make sure to write down even the smallest piece of information, because
it may turn out to be the most important.
2. Do not touch anything until a road test and a thorough visual inspection of the vehicle have been carried out. Leave the
tire pressures and vehicle load just where they were when the condition was first observed. Adjusting tire pressures,
vehicle load or making other adjustments may reduce the conditions intensity to a point where it cannot be identified
clearly. It may also inject something new into the system, preventing correct diagnosis.
3. Make a visual inspection as part of the preliminary diagnosis routine, writing down anything that does not look right.
Note tire pressures, but do not adjust them yet. Note leaking fluids, loose nuts and bolts, or bright spots where
components may be rubbing against each other. Check the luggage compartment for unusual loads.
4. Road test the vehicle and define the condition by reproducing it several times during the road test.
5. Carry out the Road Test Quick Checks as soon as the condition is reproduced. This will identify the correct diagnostic
procedure. Carry out the Road Test Quick Checks more than once to verify they are providing a valid result. Remember,
the Road Test Quick Checks may not tell where the concern is, but they will tell where it is not.
Road Test Quick Checks
1. 24-80 km/h (15-50 miles/h): With light acceleration, a moaning noise is heard and possibly a vibration is felt in the
front floor pan. It is usually worse at a particular engine speed and at a particular throttle setting during acceleration at
that speed. It may also produce a moaning sound, depending on what component is causing it. Refer to Tip-In Moan in
the Symptom Chart.
2. Acceleration/deceleration: With slow acceleration and deceleration, a shake is sometimes noticed in the steering
wheel/column, seats, front floor pan, front door trim panel or front end sheet metal. It is a low frequency vibration
(around 9-15 cycles per second). It may or may not be increased by applying brakes lightly. Refer to Idle Boom/Shake
/Vibration in the Symptom Chart.
3. High speed: A vibration is felt in the front floor pan or seats with no visible shake, but with an accompanying sound or
rumble, buzz, hum, drone or booming noise. Coast with the clutch pedal depressed or shift control selector lever in
neutral and engine idling. If vibration is still evident, it may be related to wheels, tires, front brake discs, wheel hubs
or front wheel bearings. Refer to High Speed Shake in the Symptom Chart.
4. Engine rpm sensitive: A vibration is felt whenever the engine reaches a particular rpm. It will disappear in neutral
coasts. The vibration can be duplicated by operating the engine at the problem rpm while the vehicle is stationary. It
can be caused by any component, from the accessory drive belt to the torque converter which turns at engine speed
when the vehicle is stopped. Refer to High Speed Shake in the Symptom Chart.
5. Noise/vibration while turning: Clicking, popping, or grinding noises may be due to a worn, damaged, or incorrectly
installed front wheel bearing, rear drive half shaft or CV joint.
6. Noise/vibration that is road speed relative: This noise/vibration can be diagnosed independent of engine speed or gear
selected (engine speed varies but torque and road speed remain constant). The cause may be a rear drive
axle/differential whine.
Road Conditions
An experienced technician will always establish a route that will be used for all NVH diagnosis road tests. The road selected
should be reasonably smooth, level and free of undulations (unless a particular condition needs to be identified). A smooth
asphalt road that allows driving over a range of speeds is best. Gravel or bumpy roads are unsuitable because of the additional
road noise produced. Once the route is established and consistently used, the road noise variable is eliminated from the test
results.
NOTE: Some concerns may be apparent only on smooth asphalt roads.
If a customer complains of a noise or vibration on a particular road and only on a particular road, the source of the concern
may be the road surface. If possible, try to test the vehicle on the same type of road.
Vehicle Preparation
Carry out a thorough visual inspection of the vehicle before carrying out the road test. Note anything which is unusual. Do not
repair or adjust any condition until the road test is carried out, unless the vehicle is inoperative or the condition could pose a
hazard to the technician.
After verifying the condition has been corrected, make sure all components removed have been installed.
Lift Test
After a road test, it is sometimes useful to do a similar test on a lift.
When carrying out the high-speed shake diagnosis or engine accessory vibration diagnosis on a lift, observe the following
precautions:
WARNING: If only one drive wheel is allowed to rotate, speed must be limited to 55 km/h (35 miles/h) indicated on the
speedometer since actual wheel speed will be twice that indicated on the speedometer. Speed exceeding 55 km/h (35 miles/h)
or allowing the drive wheel to hang unsupported could result in tire disintegration, differential failure, constant velocity joint
and drive half shaft failure, which could cause serious personal injury and extensive vehicle damage. Failure to follow these
instructions may result in personal injury.
CAUTION: The suspension should not be allowed to hang free. When the CV joint is run at a very high angle, extra
vibration as well as damage to the seals and joints can occur.
The rear suspension lower arm should be supported as far outboard as possible. To bring the vehicle to its correct ride height,
the full weight of the vehicle should be supported in the rear by floor jacks. REFER to: (100-02 Jacking and Lifting)
Jacking (Description and Operation), Lifting (Description and Operation).
1. Raise and support the vehicle. REFER to: (100-02 Jacking and Lifting)
Jacking (Description and Operation), Lifting (Description and Operation).
2. Explore the speed range of interest using the Road Test Quick Checks as previously described.
3. Carry out a coast down in neutral. If the vehicle is free of vibration when operating at a steady indicated speed and
behaves very differently in drive and coast, a transmission concern is likely.
Note, however, that a test on the lift may produce different vibrations and noises than a road test because of the effect of the
lift. It is not unusual to find vibrations on the lift that were not found in the road test. If the condition found on the road can
be duplicated on the lift, carrying out experiments on the lift may save a great deal of time.
Exhaust Neutralization Procedure
1. Raise vehicle on lift and slacken all exhaust fixings.
2. With all fixings loose, neutralize the exhaust system.
3. Tighten all fixings to correct torque, starting at the rear-most point working towards the front of the vehicle.
Symptom Chart
Symptom Possible Cause Action High-speed shake
Wheel end vibration
Engine/transmission
Driveline GO to Pinpoint Test A. Tip-in moan
Air cleaner
Power steering
Powertrain
Engine mounts
Exhaust system GO to Pinpoint Test B. Idle boom/shake/vibration, or shudder
Cable(s)/hoses(s)
Intake air distribution and filtering system
Engine mounts
Exhaust system
Belt/pulleys GO to Pinpoint Test C. Wheel end vibration analysis
Suspension/rear drive halfshaft and CV joints
Tires/wheels
Wheel bearings
CV joint boots GO to Pinpoint Test D. Non-axle noise
Trim/mouldings
A/C system
Accessories GO to Pinpoint Test E. Pinpoint Tests
NOTE: These Pinpoint Tests are designed to take the technician through a step-by-step diagnosis procedure to determine
the cause of a condition. It may not always be necessary to follow the chart to its conclusion. Carry out only the Pinpoint Test
steps necessary to correct the condition. Then check operation of the system to make sure the condition is corrected.
After verifying that the condition has been corrected, make sure all components removed have been installed.
PINPOINT TEST A : HIGH-SPEED SHAKE TEST DETAILS/RESULTS/ACTIONS www.JagDocs.com
Tire beads correctly seated Are the tires OK? Yes
GO to D2. No
Inspect the wheels. For additional information, refer to Section 204-00. D2: INSPECT WHEEL BEARINGS 1 Inspect the wheel bearings. For additional information, refer to Section 204-00. Are the wheel bearings OK? Yes
GO to D3. No
Repair as necessary. Repeat the Road Test as outlined. D3: INSPECT THE CONSTANT VELOCITY (CV) JOINT BOOTS 1 Inspect the CV joint boots. Spin the rear tire by hand
Inspect for evidence of cracks, tears, splits or splattered grease Are the CV joint boots OK? Yes
GO to D4. No
Repair as necessary. Repeat the Road Test as outlined. D4: INSPECT WHEEL AND TIRE RUNOUT 1 Inspect the wheel and tire runout. Carry out the Wheel and Tire Check procedure.
REFER to: Lifting (100-02 Jacking and Lifting, Description and Operation). Is the wheel and tire runout OK? Yes
Balance the wheels and tires. Refer to the wheel balance equipment manufacturers instructions.
No
Repair as necessary.
REFER to: Lifting (100-02 Jacking and Lifting, Description and Operation). Repeat the Road Test as outlined.
PINPOINT TEST E : NON-AXLE NOISE TEST
CONDITIONS DETAILS/RESULTS/ACTIONS E1: INSPECT VEHICLE TRIM 1 Check the grille and trim mouldings to see if they are the source of the noise. Are the vehicle trim components causing the noise? Yes
Install new trim or repair as necessary. For additional information, refer to Section 501-08.
No
GO to E2. E2: CHECK THE A/C SYSTEM FOR NOISE 1 Check the A/C system components for noise by turning the A/C system on and off. Is the A/C system causing the noise? Yes
Diagnose the A/C system.
REFER to: Lifting (100-02 Jacking and Lifting, Description and Operation). No
GO to E3. E3: CHECK NON-FACTORY ACCESSORIES 1 Inspect any accessories for being the source of the noise. Example: grounding body-to-frame, antennas, visors, bug deflectors and fog lights? Are the accessories the cause of the noise? Yes
Adjust, repair or install new accessories or fasteners as required.
No
Verify the customer concern.
Front Suspension (204-01 Front Suspension, Description and Operation), Front Suspension (204-01 Front Suspension, Description and Operation), Rear Suspension (204-02 Rear Suspension, Description and Operation), Rear Suspension (204-02 Rear Suspension, Description and Operation), Rear Suspension (204-02 Rear Suspension, Description and Operation).
Inspection and Verification
1. Verify the customer concern by carrying out a road test on a smooth road. If any vibrations are apparent, refer to
section 100-04 Noise, Vibration and Harshness.
2. Visually inspect for obvious signs of damage and system integrity.
3. If an obvious cause for an observed or reported condition is found, correct the cause (if possible) before proceeding to
the next step.
4. If the fault is not visually evident, verify the symptom and refer to the following Symptom Chart.
Symptom Chart
Symptom Possible Sources Action Crabbing * Incorrect rear thrust angle. * Check the rear toe adjustment.
REFER to: Rear Toe Adjustment (204-00 Suspension System - General Information, General Procedures). * Front or rear suspension components.
* Inspect the front and rear suspension systems. Repair or
install new suspension components as necessary. * Drive axle damaged. * Install a new rear drive axle/differential.
REFER to: Axle Assembly - V6 3.0L Petrol (205-02 Rear Drive Axle/Differential, Removal and Installation). Drift/Pull * Unequal tire pressure.
* Check and adjust the tire pressures. Inspect the tire for
excessive wear.
REFER to: Specifications (204-04 Wheels and Tires, Specifications). * Incorrect wheel alignment.
* Check and adjust the wheel alignment. REFER to:
(204-00 Suspension System - General Information)
Front Toe Adjustment (General Procedures), Rear Toe Adjustment (General Procedures), Camber and Caster Adjustment (General Procedures). * Tires.
* Check and adjust the tire pressures. Inspect the tire for
excessive wear.
REFER to: Specifications (204-04 Wheels and Tires, Specifications). * Unevenly loaded or overloaded vehicle. * Notify the customer of incorrect vehicle loading. * Damaged steering components. * Check the steering system. * Brake drag. * Check the brakes.
REFER to: Brake System (206-00 Brake System - General Information, Diagnosis and Testing). Mechanical
Damaged tires
Wheel bearing(s)
Loose or damaged front or rear suspension components
Loose, damaged or missing suspension fastener(s)
Incorrect spring usage
Damaged or sagging spring(s)
Damaged or leaking shock absorber(s)
Damaged or leaking strut(s)
Worn or damaged suspension bushing(s)
Loose, worn or damaged steering system components
Damaged axle components Visual Inspection Chart
Removal and Installation),
Shock Absorber and Spring Assembly (204-02 Rear Suspension, Removal and Installation). Incorrect Tire Wear
* Incorrect tire pressure (rapid center rib
or inner and outer edge wear). * Check and adjust the tire pressure. Inspect the tire for
excessive wear.
REFER to: Specifications (204-04 Wheels and Tires, Specifications). * Excessive front or rear toe (rapid inner
or outer edge wear). * Check and adjust the wheel alignment. REFER to:
(204-00 Suspension System - General Information)
Front Toe Adjustment (General Procedures), Rear Toe Adjustment (General Procedures), Camber and Caster Adjustment (General Procedures). * Excessive negative or positive camber
(rapid inner or outer edge wear). * Check and adjust the wheel alignment. REFER to:
(204-00 Suspension System - General Information)
Front Toe Adjustment (General Procedures), Rear Toe Adjustment (General Procedures), Camber and Caster Adjustment (General Procedures). * Tires out of balance (tires cupped or dished). * Balance the tires. Rough ride * Spring(s)
* Check and install new spring(s) as necessary. REFER to:
Front Shock Absorber (204-01 Front Suspension, Removal and Installation),
Shock Absorber and Spring Assembly (204-02 Rear Suspension, Removal and Installation). Shimmy or Wheel Tramp * Loose wheel nut(s).
* Check and tighten the wheel nuts to specification.
REFER to: Specifications (204-04 Wheels and Tires, Specifications). * Loose front suspension fasteners.
* Check and tighten the suspension fasteners to
specification.
REFER to: Specifications (204-00 Suspension System - General Information, Specifications). * Front wheel bearing(s). * Check the wheel bearings. * Worn or damaged suspension component bushing. * Check and install new components as necessary. * Wheel/tires.
* Check the wheels/tires. Balance or install new
wheel/tires as necessary.
REFER to: Wheels and Tires (204-04 Wheels and Tires, Diagnosis and Testing). * Loose, worn or damaged ball joint(s). * Check the Ball Joint(s). * Loose, worn or damaged steering components. * Check and install new components as necessary. * Front wheel alignment.
* Check and adjust the wheel alignment. REFER to:
(204-00 Suspension System - General Information)
Front Toe Adjustment (General Procedures), Rear Toe Adjustment (General Procedures), Camber and Caster Adjustment (General Procedures). * Shock absorber(s). * Check and install new shock absorber(s) as necessary.
REFER to:
Front Shock Absorber (204-01 Front Suspension, Removal and Installation),
Shock Absorber and Spring Assembly (204-02 Rear Suspension, Removal and Installation). * Spring(s).
* Check and install new springs as necessary. REFER to:
Front Shock Absorber (204-01 Front Suspension, Removal and Installation),
Shock Absorber and Spring Assembly (204-02 Rear Suspension, Removal and Installation). Poor self center action of
the steering * Ball joints. * Check the Ball Joints. * Steering components. * Check and install new components as necessary. Steering wheel off-center * Unequal front or rear toe settings.
* Check and adjust the wheel alignment. REFER to:
(204-00 Suspension System - General Information)
Front Toe Adjustment (General Procedures), Rear Toe Adjustment (General Procedures), Camber and Caster Adjustment (General Procedures). * Steering components. * Check and install new components as necessary. Sway or roll
* Overloaded, unevenly or incorrectly
loaded vehicle. * Notify the customer of incorrect vehicle loading. * Loose wheel nut(s).
* Check and tighten the wheel nut(s) to specification.
REFER to: Specifications (204-04 Wheels and Tires, Specifications). * Coil spring(s).
* Check and install new coil springs as necessary. REFER
to:
Front Shock Absorber (204-01 Front Suspension, Removal and Installation),
Shock Absorber and Spring Assembly (204-02 Rear Suspension, Removal and Installation). * Loose front stabilizer bar or rear
stabilizer bar. * Check and tighten the stabilizer bar to specification.
REFER to:
Specifications (204-01 Front Suspension, Specifications), Specifications (204-02 Rear Suspension, Specifications). * Worn lower suspension arm stabilizer
bar insulators. * Install new lower suspension arm stabilizer bar as
necessary. REFER to:
Front Stabilizer Bar - 2.7L Diesel (204-01, Removal and
Installation),
Front Stabilizer Bar - V6 3.0L Petrol (204-01 Front Suspension, Removal and Installation),
Front Stabilizer Bar - 4.2L (204-01, Removal and
Installation),
Rear Stabilizer Bar (204-02 Rear Suspension, Removal and Installation). * Shock absorber(s). * Check and install new shock absorber(s) as necessary.
REFER to:
Front Shock Absorber (204-01 Front Suspension, Removal and Installation),
Shock Absorber and Spring Assembly (204-02 Rear Suspension, Removal and Installation). Vehicle Leans to One
Side * Unevenly loaded or overloaded vehicle. * Notify the customer of incorrect vehicle loading. * Front or rear suspension components.
* Inspect the front and rear suspension systems. Repair or
install new suspension components as necessary. * Shock absorber(s). * Check and install new shock absorber(s) as necessary.
REFER to:
Front Shock Absorber (204-01 Front Suspension, Removal and Installation),
Shock Absorber and Spring Assembly (204-02 Rear Suspension, Removal and Installation). * Coil spring(s).
* Check and install new spring(s) as necessary. REFER to:
Front Shock Absorber (204-01 Front Suspension, Removal and Installation),
Shock Absorber and Spring Assembly (204-02 Rear Suspension, Removal and Installation). * Incorrect ride height. Lateral tilt out of
specification. * Check the ride height. Install new spring(s) as
necessary. REFER to:
Front Shock Absorber (204-01 Front Suspension, Removal and Installation),
Shock Absorber and Spring Assembly (204-02 Rear Suspension, Removal and Installation). Vibration/Noise * Tires/wheels.
* Wheel bearings.
* Wheel hubs.
* Brake components.
* Suspension components.
* Steering components. * Check and install new components as necessary. Wander * Unevenly loaded or overloaded vehicle. * Notify the customer of incorrect vehicle loading. * Ball joint(s). * Check the Ball Joint(s). * Front wheel bearing(s). * Check the wheel bearings. * Loose, worn or damaged suspension components. * Check and install new suspension components as necessary. * Loose suspension fasteners.
* Check and tighten the suspension fasteners to
specification.
REFER to: Specifications (204-00 Suspension System - General Information, Specifications). * Steering components. * Check and install new steering components. * Wheel alignment (excessive total front
toe-out). * Check and adjust the wheel alignment. REFER to:
(204-00 Suspension System - General Information)
Front Toe Adjustment (General Procedures), Rear Toe Adjustment (General Procedures), Camber and Caster Adjustment (General Procedures). Component Tests
Ball Joint Inspection
NOTE: The front suspension is shown in the following procedures. The inspection of the rear suspension upper ball joint
is similar.
1. Raise and support the vehicle. REFER to: (100-02 Jacking and Lifting)
Jacking (Description and Operation), Lifting (Description and Operation).
2. Prior to carrying out any inspection of the ball joints, inspect the front wheel bearings.
Published: 16-Oct-2013
Suspension System - General Information - Four-Wheel Alignment
General Procedures
CAUTIONS:
Make sure the vehicle is on a flat level surface.
Make sure the tire pressures are within specification.
Make sure that only the manufacturers' recommended four wheel alignment equipment is used.
Make sure the steering is in the straight ahead position.
1. For wheel alignment information, refer to the suspension specification
section.
For additional information, refer to: Specifications (204-00 Suspension System - General Information, Specifications).
2. Check the tie rod ends, suspension joints, wheel bearings and wheels
and tires for damage, wear and free play.
Adjust or repair any worn, damaged or incorrectly adjusted
components.
3. Check and adjust tire pressures.
4. Position the vehicle on a calibrated, level, vehicle lift.
5. Vehicles with air suspension.
For additional information, refer to: Air Suspension Manual Tight
Tolerance Setting Mode (204-05, General Procedures).
6. Release the vehicle parking brake.
7. Using only four-wheel alignment equipment approved by Jaguar, check
the wheel alignment.
8. NOTE: LH illustration shown, RH is similar. To
adjust, loosen the toe link locknuts. www.JagDocs.com