Jaguar XJ (X350). Manual — part 136

5

Year Built

6

Month Built

7

Day Built

8

Plant Built

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C = Castle Bromwich

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B = Browns Lane

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G = German Specification

Engine capacity

Transmission Axle Ratio

4.2L V8 Supercharger Automatic

2:87

4.2L V8

Automatic

2:87

3.5 V8

Automatic

3.07

3.0 V6

Automatic

3.31

The plant code denotes a particular rear drive axle design and specific ratio. In addition, the plant

code will not change as long as that particular rear drive axle never undergoes an external design

change. If, however, an internal design change takes place during the production life of the rear drive

axle and that internal change affects parts interchangeability, a dash and numerical suffix is added to

the plant code. This means that as an assembly both rear drive axles are interchangeable; however,

internally they are different. Therefore, each requires different internal parts at the time of repair.

Diagnosis and testing

Driveline System

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,

Noise, Vibration and Harshness (NVH)

1 . Verify the customer concern by carrying out a road test of the vehicle.

2 . Visually inspect for obvious signs of mechanical damage.

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.

Rear Drive Axle Noise

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.

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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.

Damage to a gear tooth on the coast side can cause a noise identical to a chuckle. A very small tooth

nick or ridge on the edge of a tooth can cause the noise.

Knock

Knock, which can occur on all driving phases, has several causes including damaged teeth or gearset.

A gear tooth damaged on the drive side is a common cause of the knock.

Clunk

Clunk is a metallic noise heard when the automatic transmission is engaged in REVERSE or DRIVE. The

noise may also occur when the throttle is applied or released. Clunk is caused by transmission

calibration, backlash in the driveline or loose suspension components and is felt or heard in the

vicinity of the rear drive axle.

Bearing Rumble

Bearing rumble sounds like marbles being tumbled. This condition is usually caused by a

worn/damaged wheel bearing. The lower pitch is because the wheel bearing turns at only about one-

third of the driveshaft speed. Wheel bearing noise also may be high-pitched, similar to gear noise,

but will be evident in all four driving modes.

Symptom Chart

Noise is at constant tone over a narrow vehicle speed range. Usually heard on light drive and coast

conditions.

Possible Source(s):

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Rear drive axle.

Action(s) to take:

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For additional information, GO to Pinpoint Test

G215971p1

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