Jaguar XJ (X350). Service manual — part 725

Vehicles with 3.5L or 4.2L engine

Item

Part Number

Description

1

—

Water pump pulley

2

—

Accessory drive belt tensioner

3

—

Power steering pump pulley

4

—

Air conditioning (A/C) compressor pulley

5

—

Crankshaft pulley

6

—

Accessory drive belt idler pulley

7

—

Generator pulley

Vehicles with supercharger

Item

Part Number

Description

1

—

Supercharger pulley

2

—

Supercharger belt idler pulley

3

—

Crankshaft pulley

4

—

Supercharger belt tensioner

Crankshaft Pulley

The combined crankshaft pulley and torsional vibration damper drives a single, six ribbed vee belt.

The belt drives all of the engine-mounted accessories such as the generator, the power assisted

steering pump, the air-conditioning compressor and the coolant water pump.

Air Conditioning Compressor Pulley

This is positioned at the lowest point of the front-end accessory drive on the left-hand side accessory

mounting.

Power Assisted Steering Pump Pulley

The power assisted steering pump pulley is located on the left-hand side, above the air conditioning

compressor.

Generator Pulley

The generator is fitted on the right-hand accessory mounting.

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Supercharger Pulley

The supercharger is located between the left-hand and right-hand cylinders and retained at three

mounting points.

Accessory drive belt tensioner and supercharger belt tensioner

The accessory drive belt tensioner and supercharger belt tensioner is calibrated to provide the

correct amount of tension to the belt for a given drive system. Unless a spring within the tensioner

assembly breaks, or some other mechanical part of the tensioner fails, there is no need to check the

tensioner for correct tension.

Accessory drive belt and supercharger belt

Item

Description

1

Acceptable drive belt cracking

2

Unacceptable drive belt damage

The accessory drive belt and the supercharger belt should be inspected at every routine service for

excessive wear and damage. A drive belt which displays symptoms of cracking may be perfectly fit for

further service.

Should cracking be detected, serviceability may be assessed using the following guidelines:

Fifteen cracks per rib over a 100 mm length of drive belt is acceptable.

Section(s) of belt missing from any rib is not acceptable and the drive belt must be renewed.

Accessory drive belt tensioner

The accessory drive belt tensioner consists of an idler pulley which is free to rotate on a bearing,

located at the end of a spring-loaded pivot arm.

The pivot arm can be turned counter-clockwise (viewed from the front of the engine) for accessory

drive belt removal and installation.

The accessory drive belt wear indicators are incorporated on the bottom of the accessory drive belt

tensioner. When the indicators are aligned the accessory drive belt requires replacing.

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