2010 JAGUAR XFR lock

A motor and reduction gearbox, attached to the cover.
A temperature sensor installed in the cover.

The DLM (differential locking module) operates the motor of the electronic differential under the control of the ADM (adaptive
damping module).
Exploded View of Electronic Differential



Item Description 1 Circlip 2 Bearing assembly 3 Input actuator 4 Actuator balls 5 Output actuator www.JagDocs.com

Thrust race 7 Shim 8 Thrust plate 9 Dished washer 10 Bolt (10 off) 11 Clutch basket 12 Multi-plate clutch and pressure disc 13 Differential case 14 Screw (2 off) 15 Bearing assembly 16 Oil seal 17 Oil slinger inner 18 Oil slinger outer 19 Input flange 20 Pinion nut 21 Collapsible spacer 22 Shim 23 Bearing assembly 24 Pinion shaft 25 Mounting insulator inner (2 off) 26 Mounting insulator rubber (2 off) 27 Mounting insulator outer (2 off) 28 Carrier 29 Oil seal 30 Drain plug 31 Vent 32 Breather cap 33 Shim 34 Bearing assembly 35 Drive gear 36 Shim 37 RH sun gear 38 Circlip 39 Thrust washer (4 off) 40 Planet gear (4 off) 41 Pin (2 off) 42 Shaft 43 LH sun gear 44 Shim 45 Bearing assembly 46 Shim 47 Dowel (2 off) 48 Bolt (4 off) 49 Reduction gear casing 50 Reduction gear 51 Shaft 52 Temperature sensor 53 O-ring seal 54 Motor 55 Screw (4 off) 56 Cover 57 Output actuator locking pin 58 Bolt (9 off)

60 Oil seal The multi-plate clutch is contained in a clutch basket attached to the differential carrier with the crown wheel securing bolts.
Alternate plates of the clutch pack are keyed to the clutch basket and the LH sun gear. A pressure disc is installed on the outer end of the clutch pack and keyed to the clutch basket. A thrust race on the end of the clutch basket incorporates lugs which
extend through the clutch basket onto the pressure disc.

The actuator assembly is mounted on bearings on the outboard end of the clutch basket, against the thrust race. The actuator
assembly consists of input and output actuators separated by five ball bearings. A locking pin in the cover engages with a slot
in the output actuator to prevent it turning, but allow it to move axially. The input actuator engages with the reduction gearbox
and is free to rotate relative to the cover. Ball bearings locate in curved grooves in the mating faces of the input and
output actuators. The bottom surface of each groove incorporates a ramp. Rotation of the input actuator forces the ball
bearings up the ramps in the grooves and induces an axial movement in the output actuator. The thrust race and pressure disc
transfer the axial movement from the output actuator to the clutch pack.



Item Description 1 Actuator 2 Multi-plate clutch 3 Differential The motor is a 12 V dc motor that adjusts the frictional loading of the multi-plate clutch, via the reduction gearbox and the
actuator assembly, under the control of the DLM. Adjusting the frictional loading of the multi-plate clutch adjusts the locking
torque between the crown wheel drive gear and the sun wheel.

Four bolts attach the motor to the reduction gearbox, which is located in position on the cover with two dowels, and secured
with four bolts. An O-ring seals the joint between the motor and the reduction gearbox.

The motor is driven by a 12 V dc feed direct from the DLM. The motor also incorporates the following connections with the
DLM:

A motor temperature sensor, to prevent excessive use from damaging the motor.
Two Hall effect motor position sensors, to enable closed loop control of the motor.

The temperature sensor provides a differential oil temperature signal to the DLM, to prevent excessive use from damaging the
multi-plate clutch.

Differential Locking Module (DLM)

The DLM controls operation of the electronic differential. The DLM is attached to a bracket located on the LH side of the luggage compartment, immediately forward of the fender tail lamp, behind the trim.

bus allows the DLM to communicate with other systems on the vehicle.

A certain amount of differential slip is required to allow the vehicle to turn corners and to remain stable under control of the
ABS. The ADM monitors the driver's demands through primary vehicle controls and automatically sets the slip torque in the differential. The system is completely automatic and does not require any special driver input.
The differential strategy in the ADM includes:

A pre-loading function, increasing locking torque with increased driving torque.
A slip controller to decrease locking torque for optimum comfort, e.g. parking.
The ADM memorizes the position of the motor when the ignition is switched off.

CAN bus messages used by the ADM include wheel speed, steering angle, automatic transmission speed, temperature information, car configuration, axle ratios and mode inputs.

The ADM also sends messages via the CAN bus to tell other control modules on the network the status of the electronic differential. The clutch torque and default mode status are some of the main signals sent out by the ADM.

If the DLM or ADM are replaced, a Jaguar approved diagnostic system must be connected to the vehicle and the differential
self-calibration procedure must be performed. This procedure must also be performed if the motor or electronic differential is
replaced.

If a fault occurs with the electronic differential, the ADM, the DLM, or one of the required input signals, the ADM records an
error code and displays a warning in the message center.
The following messages can be displayed:

Message Description Chime E-DIFF NOT
AVAILABLE Differential temperature has reached the overheat threshold. System deactivated until temperature
returns within limits. Single E-DIFF FAULT Fault has occurred with electronic differential. System deactivated until fault rectified. Single

Rear Drive Axle/Differential - Differential Locking Motor
Removal and Installation

Removal


NOTE: Removal steps in this procedure may contain installation details. Published: 26-Feb-2014

1. Refer to: Differential Draining and Filling (205-02 Rear Drive Axle/Differential, General Procedures).

2.
3.

Published: 11-May-2011
Rear Drive Halfshafts - Rear Drive Halfshafts - System Operation and
Component Description
Description and Operation

System Operation



Rear Drive Halfshafts Component Description

The solid-steel halfshafts are of unequal length, with each halfshaft comprising inner and outer CV (constant velocity) joints.
The CV joints are the 'ball and socket' type packed with grease and protected by gaiters.

The outer CV joint is an interference fit into the wheel hub and secured by a locking nut. The inner CV joint is a slide fit and is
retained in the differential with a spring clip.
www.JagDocs.com

9.
















10.
11. CAUTION: Install the halfshaft nut finger tight.


NOTE: Do not fully tighten the locking nut at this
stage.













CAUTION: The final tightening of the suspension
components must be carried out with the vehicle on its
wheels.
Torque: 150 Nm













CAUTION: The final tightening of the suspension
components must be carried out with the vehicle on its
wheels.
Torque: 55 Nm

If the concern becomes evident during this check, verify it fits the description given before the road test. If the concern is not
evident, attempt to duplicate the condition using the information from the description.

If a concern exists, use the Symptom Chart in order to isolate it to a specific sub-system and condition description. From this
description, a list of possible sources can be used to further narrow the cause to a specific component or condition.

Symptom Chart

Symptom Possible Cause Action Brakes noisy
Brake pads
Brake discs GO to Pinpoint Test A. Vibration when brakes are
applied
Wheels/tires out of balance
Wheel hub nuts loose
Brake caliper mounting bolts loose
Brake pads
Foreign material/scratches/corrosion
on brake disc contact surfaces
Excessive brake disc thickness
variation
Excessive brake disc runout
Wheel bearing wear or failure
Suspension bushing wear or failure
Steering bushing wear or failure GO to Pinpoint Test B. The brakes pull or drift
Tire pressures/wear
Brake calipers
Brake pads
Brake discs
Wheel alignment adjustment
Wheel bearing
Suspension bushings and ball joints GO to Pinpoint Test C. The pedal feels spongy
Air in brake hydraulic system
Leak in hydraulic system
Brake booster/master cylinder
Brake pads GO to Pinpoint Test D. The pedal goes down fast
Air in brake hydraulic system
Leak in hydraulic system
Brake booster/master cylinder
Brake pads GO to Pinpoint Test E. The pedal goes down
slowly
Air in brake hydraulic system
Brake booster/master cylinder GO to Pinpoint Test F. Excessive brake pedal
effort required
Brake pads
Brake booster GO to Pinpoint Test G. Brake lockup during light
brake pedal force
Brake pads
Brake calipers GO to Pinpoint Test H. Brakes drag
Parking brake control
applied/malfunction
Seized parking brake cables
Seized brake caliper slide pins
Seized brake caliper
Brake booster
Pedal gear GO to Pinpoint Test I. Excessive/Erratic brake
pedal travel
Hydraulic system
Brake pads Brake
discs
Hub and bearing assembly GO to Pinpoint Test J. The red brake warning
indicator is always on
Fluid level
Brake master cylinder fluid level
sensor
Parking brake control Fill the system to specification. Check for leaks.
Install a new brake master cylinder fluid reservoir as
required.
REFER to: Brake Fluid Reservoir (206-06 Hydraulic Brake Actuation, Removal and Installation).