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
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
7 Rear accelerometer 8 Instrument cluster 9 JaguarDrive selector module 10 ABS (anti-lock brake system) module 11 TCM (transmission control module) 12 ECM (engine control module) 13 RH (right-hand) rear damper 14 RH front damper 15 LH (left-hand) front damper 16 LH rear damper 17 LH rear suspension height sensor 18 RH rear suspension height sensor 19 LH front suspension height sensor 20 RH front accelerometer 21 RH front suspension height sensor 22 Adaptive damping module 23 LH front accelerometer
PRINCIPLES OF OPERATION System Operation
The adaptive damping module uses a combination of information from other system modules and data from the accelerometers
and suspension height sensors to measure the vehicle and suspension states and driver inputs. Using this information, the
adaptive damping module applies algorithms to control the dampers for the current driving conditions.
The adaptive damping module receives signals on the high speed CAN bus from the following system components: Brake Pressure - ABS module. Brake Pressure Quality Factor - ABS module. Car Configuration Parameters - AJB. Center Differential Range Actual - ECM. Engine Speed - ECM. Engine Speed Quality Factor - ECM. Engine Torque Flywheel Actual - ECM. Engine Torque Flywheel Actual Quality Factor - ECM. Gear Position Target - TCM. Lateral Acceleration - ABS module. Power Mode (Ignition Signal) - CJB. Power Mode Quality Factor - CJB. Roll Stability Control Mode - ABS module. Steering Wheel Angle - ABS module. Steering Wheel Angle Speed - ABS module. Steering Wheel Angle Status - ABS module. Terrain Mode Requested - JaguarDrive selector.
Torque Converter Slip - TCM. Vehicle Information Parameters HS - AJB Vehicle Speed - ABS module. Vehicle Speed Quality Factor - ABS module. Front Left Wheel Speed - ABS module. Front Left Wheel Speed Quality Factor - ABS module. Front Right Wheel Speed - ABS module. Front Right Wheel Speed Quality Factor - ABS module. Rear Left Wheel Speed - ABS module. Rear Left Wheel Speed Quality Factor - ABS module. Rear Right Wheel Speed Quality Factor - ABS module. Rear Right Wheel Speed - ABS module. The adaptive damping module also outputs information on the high speed CAN bus for use by other systems as follows: Fault Message - instrument cluster.
Terrain Mode Change Status - JaguarDrive selector.
Terrain Mode - JaguarDrive selector.
The adaptive damping module monitors the input signals and operates the damper solenoids. The input signals are used in
control modes and a force required for each damper for that mode is calculated. An arbitration mode monitors the force
requirements from each mode and apportions a force to a damper. The force is converted to the appropriate current and sent to
the damper.
The control modes are as follows:
Driveline System - General Information - Driveline System
Diagnosis and Testing
Principle of Operation Published: 11-May-2011
For a detailed description of driveline operation, refer to the relevant Description and Operation section in the workshop
manual. REFER to:
Driveshaft (205-01 Driveshaft, Description and Operation), Driveshaft (205-01 Driveshaft, Description and Operation), Driveshaft (205-01 Driveshaft, Description and Operation), Rear Drive Axle and Differential (205-02, Description and Operation),
Rear Drive Axle and Differential (205-02, Description and Operation),
Rear Drive Axle and Differential (205-02, Description and Operation),
Rear Drive Halfshafts (205-05 Rear Drive Halfshafts, Description and Operation), Rear Drive Halfshafts (205-05 Rear Drive Halfshafts, Description and Operation), Rear Drive Halfshafts (205-05 Rear Drive Halfshafts, Description and Operation).
Inspection and Verification
CAUTION: Only serviceable items can be renewed or adjusted. Failure to follow this instruction may result in the warranty
of the component being rejected.
Certain driveline trouble symptoms are also common to the engine, transmission, wheel bearings, tires, and other parts of the
vehicle. For this reason, make sure that the cause of the trouble is in the driveline before adjusting, repairing, or installing any
new components. For additional information, refer to Workshop Manual section 100-04 Noise, Vibration and Harshness.
1. Verify the customer concern by carrying out a road test of the vehicle.
2. Visually inspect for obvious signs of mechanical damage and system integrity.
3. If an obvious cause for an observed or reported concern is found, correct the cause (if possible) before proceeding to
the next step.
4. If the concern is not visually evident, verify the symptom and refer to the Symptom Chart.
Identify the Condition
Gear Howl and Whine
Howling or whining of the ring gear and pinion is due to an incorrect gear pattern, gear damage or incorrect bearing preload.
Bearing Whine
Bearing whine is a high-pitched sound similar to a whistle. It is usually caused by worn/damaged pinion bearings, which are
operating at driveshaft speed. Bearing noise occurs at all driving speeds. This distinguishes it from gear whine which is speed
dependent.
As noted, pinion bearings make a high-pitched, whistling noise, usually at all speeds. If however there is only one pinion
bearing that is worn/damaged, the noise may vary in different driving phases.
A wheel bearing noise can be mistaken for a pinion bearing noise.
Chuckle
Chuckle that occurs on the coast driving phase is usually caused by excessive clearance between the differential gear hub and
the differential case bore. www.JagDocs.com
Symptom Possible Cause Action rear drive halfshaft
Wheel bearings, brakes or
suspension components Vibration at highway speeds
Out-of-balance wheel(s) or tire(s)
Driveline out of
balance/misalignment
Driveshaft center bearing touching
body mounting point
Balance and install new wheel(s) and tire(s)
as required
REFER to: Wheel and Tire (204-04 Wheels and Tires, Removal and Installation).
For additional information,
REFER to: Driveline Angle Inspection (205-00 Driveline System - General Information,
General Procedures).
Refer to the Manufacturer approved
diagnostic system for driveshaft balancing
application
Check for correct spacer washer thickness.
Inspect and install new washers as required Shudder, Vibration During
Acceleration
Powertrain/driveline misalignment
High constant velocity (CV) joint
operating angles caused by
incorrect ride height
Check for misalignment. Install new
components as required. For driveshaft
alignment,
REFER to: Driveline Angle Inspection (205-00 Driveline System - General Information,
General Procedures).
Check the ride height and verify the correct
spring rate. Install new components as
required Lubricant Leak
Rear drive axle breather
Damaged seal
Rear drive axle filler plug
Rear drive axle rear cover joint
Check oil level and correct as required
Install new components as required Pinpoint Tests
PINPOINT TEST A : EXCESSIVE DRIVELINE NOISE TEST
CONDITIONS DETAILS/RESULTS/ACTIONS A1: CHECK NOISE FROM VEHICLE ON ROAD TEST 1 Road test vehicle to determine load and speed conditions when noise occurs. 2 Assess the noise with different gears selected. Does the noise occur in different gears at the same vehicle speed? Yes
Install a new rear drive axle/differential assembly.
REFER to: Axle Assembly - V6 3.0L Petrol (205-02 Rear Drive Axle/Differential, Removal and Installation).
Re-test the system for normal operation.
No
Suspect the engine or transmission. For additional information, REFER to:
Engine - 3.0L/4.2L (303-00 Engine System - General Information, Diagnosis and Testing), Engine - 2.7L Diesel (303-00 Engine System - General Information, Diagnosis and Testing), Diagnostic Strategy (307-01A Automatic Transmission/Transaxle - V6 3.0L Petrol, Diagnosis and Testing).
1 Transmission flexible joint 2 Collapsible front driveshaft tube 3 Splined slip joint 4 Center bearing 5 Universal joint 6 Rear driveshaft tube 7 Differential flexible joint
Driveshaft - Driveshaft - Overview
Description and Operation
Driveshaft Overview Published: 11-May-2011
The two-piece driveshaft, manufactured from lightweight tubular steel, transmits drive from the engine, via the transmission,
to the differential. The driveshaft aligns with the centerline of the vehicle’s body and is supported by a center bearing.
Published: 11-May-2011
Driveshaft - Driveshaft - System Operation and Component Description
Description and Operation
Driveshaft System Operation
The two-piece driveshaft, manufactured from lightweight tubular steel, transmits drive from the engine, via the transmission,
to the differential. The driveshaft aligns with the centerline of the vehicle’s body and is supported by a center bearing.
The driveshaft's front tube is of swaged construction, which is a crash energy management feature, designed to collapse
progressively and predictably in the event of a severe frontal impact. A low-friction splined slip-joint at the center of the
driveshaft provide the driveshaft's plunge capability.
Flexible couplings connecting the driveshaft to both the transmission and the differential counteract the angular movement of
the driveshaft caused by the driveline's acceleration and braking forces.
The center universal joint is positioned at a specified angle using shims between the center bearing and the vehicle's body.
The driveline angles have been carefully configured to balance minimum power losses with excellent vibration and wear
characteristics. The universal joint is lubricated during manufacture and sealed for life.
www.JagDocs.com