2010 JAGUAR XFR clutch

1 Sprags 2 Inner race 3 Outer race 4 Sprag and cage assembly 5 Sprag outer race 6 Sprag inner race 7 Retaining ring The free wheel clutch can perform three functions; hold the stator stationary, drive the stator and free wheel allowing the
stator to rotate without a drive output. The free wheel clutch used in the ZF 6HP28 transmission is of the sprag type and
comprises an inner and outer race and a sprag and cage assembly. The inner and outer races are pressed into their related
components with which they rotate. The sprag and cage assembly is located between the inner and outer races.

The sprags are located in a cage which is a spring which holds the sprags in the 'wedge' direction and maintains them in
contact with the inner and outer races.

Referring to the illustration, the sprags are designed so that the dimension 'B' is larger than the distance between the inner
and outer race bearing surfaces. When the outer race rotates in a clockwise direction, the sprags twist and the edges across
the dimension 'B' wedge between the races, providing a positive drive through each sprag to the inner race. The dimension 'A'
is smaller than the distance between the inner and outer race bearing surfaces. When the outer race rotates in an
anti-clockwise direction, the dimension 'A' is too small to allow the sprags to wedge between the races, allowing the outer
race to rotate freely.

On the illustration shown, when the outer race is rotated in a clockwise direction, the sprags twist and are 'wedged' between
the inner and outer races. The sprags then transfer the rotation of the outer race to the inner race, which rotates at the same
speed.

Lock-Up Clutch Mechanism

The TCC (torque converter clutch) is hydraulically controlled by an EPRS, which is controlled by the TCM. This allows the torque converter to have three states of operation as follows:
• Fully engaged
• Controlled slip variable engagement
• Fully disengaged.

The TCC is controlled by two hydraulic spool valves located in the valve block. These valves are actuated by pilot pressure supplied via a solenoid valve which is also located in the valve block. The solenoid valve is operated by PWM (pulse width One Way Free Wheel Clutch – Typical

Item Description A Unlocked condition B Locked condition 1 Clutch plate 2 Clutch piston 3 Torque converter body 4 Turbine 5 Impeller 6 Stator 7 Piston chamber 8 Turbine chamber The lock-up clutch is a hydro-mechanical device which eliminates torque converter slip, improving fuel consumption. The
engagement and disengagement is controlled by the TCM to allow a certain amount of controlled 'slip'. This allows a small difference in the rotational speeds of the impeller and the turbine which results in improved shift quality. The lock-up clutch
comprises a piston and a clutch friction plate.

In the unlocked condition, the oil pressure supplied to the piston chamber and the turbine chamber is equal. Pressurized fluid
flows through a drilling in the turbine shaft and through the piston chamber to the turbine chamber. In this condition the clutch
plate is held away from the torque converter body and torque converter slip is permitted.

In the locked condition, the TCC spool valves are actuated by the EPRS. The fluid flow in the unlocked condition is reversed and the piston chamber is vented. Pressurized fluid is directed into the turbine chamber and is applied to the clutch piston.
The piston moves with the pressure and pushes the clutch plate against the torque converter body. As the pressure increases,
the friction between the clutch plate and the body increases, finally resulting in full lock-up of the clutch plate with the body.
In this condition there is direct mechanical drive from the engine crankshaft to the transmission planetary gear train.

FLUID PUMP

The fluid pump is an integral part of the transmission. The fluid pump is used to supply hydraulic pressure for the operation of
the control valves and clutches, to pass the fluid through the transmission cooler and to lubricate the gears and shafts.
The ZF 6HP28 fluid pump is a crescent type pump and is located between the intermediate plate and the torque converter. The
pump has a delivery rate of 16 cm3
per revolution.

transmission functions. The Mechatronic valve block comprises the following components:
TCM

Pressure regulator solenoids
Shift control solenoid
Damper
Hydraulic spool valves
Selector valve
Temperature sensor
Turbine speed sensor
Output shaft speed sensor.
Sensors

Speed Sensors

The turbine speed sensor and the output shaft speed sensor are Hall effect type sensors located in the Mechatronic valve block
and are not serviceable items. The TCM monitors the signals from each sensor to determine the input (turbine) speed and the output shaft speed.

The turbine speed is monitored by the TCM to calculate the slip of the torque converter clutch and internal clutch slip. This signal allows the TCM to accurately control the slip timing during shifts and adjust clutch application or release pressure for overlap shift control.

The output shaft speed is monitored by the TCM and compared to engine speed signals received on the CAN bus from the ECM. Using a comparison of the two signals the TCM calculates the transmission slip ratio for plausibility and maintains adaptive pressure control.
Temperature Sensor

The temperature sensor is also located in the Mechatronic valve block. The TCM uses the temperature sensor signals to determine the temperature of the transmission fluid. These signals are used by the TCM to control the transmission operation to promote faster warm-up in cold conditions or to assist with fluid cooling by controlling the transmission operation when high
fluid temperatures are experienced. If the sensor fails, the TCM will use a default value and a fault code will be stored in the TCM.
Damper

There is one damper located in the valve housing. The damper is used to regulate and dampen the regulated pressure supplied
via EPRS. The damper is load dependent through modulation of the damper against return spring pressure.

The damper comprises a piston, a housing bore and a spring. The piston is subject to the pressure applied by the spring. The
bore has a connecting port to the function to which it applies. Fluid pressure applied to the applicable component (i.e. a
clutch) is also subjected to the full area of the piston, which moves against the opposing force applied by the spring. The
movement of the piston creates an action similar to a shock absorber, momentarily delaying the build up of pressure in the
circuit. This results in a more gradual application of clutches improving shift quality.

Spool Valves

The valve block spool valves control various functions of the transmission. The spool valves are of conventional design and are
operated by fluid pressure.

Each spool valve is located in its spool bore and held in a default (unpressurized) position by a spring. The spool bore has a
number of ports which allow fluid to flow to other valves and clutches to enable transmission operation. Each spool has a
piston which is waisted to allow fluid to be diverted into the applicable ports when the valve is operated.

When fluid pressure moves a spool, one or more ports in the spool bore are covered or uncovered. Fluid is prevented from
flowing or is allowed to flow around the applicable waisted area of the spool and into another uncovered port. The fluid is
either passed through galleries to actuate another spool, operate a clutch or is returned to the fluid pan.

DRIVE CLUTCHES



Item Description 1 Input shaft 2 Main pressure supply port 3 Piston 4 Cylinder – external plate carrier 5 Clutch plate assembly 6 Baffle plate 7 Diaphragm spring 8 Output shaft 9 Bearing 10 Dynamic pressure equalization chamber 11 Piston chamber 12 Lubrication channel There are three drive clutches and two brake clutches used in the ZF 6HP28 transmission. Each clutch comprises one or more
friction plates dependent on the output controlled. A typical clutch consists of a number of steel outer plates and inner plates
with friction material bonded to each face.

On 5.0L SC (supercharger) and 3.0L diesel models, the uprated transmission includes additional clutch plates to enable the
transmission to manage the additional power output from these engines.

The clutch plates are held apart mechanically by a diaphragm spring and hydraulically by dynamic pressure. The pressure is
derived from a lubrication channel which supplies fluid to the bearings etc. The fluid is passed via a drilling in the output shaft
into the chamber between the baffle plate and the piston. To prevent inadvertent clutch application due to pressure build up
produced by centrifugal force, the fluid in the dynamic pressure equalization chamber overcomes any pressure in the piston
chamber and holds the piston off the clutch plate assembly.

When clutch application is required, main pressure from the fluid pump is applied to the piston chamber from the supply port.
This main pressure overcomes the low pressure fluid present in the dynamic pressure equalization chamber. The piston moves,
against the pressure applied by the diaphragm spring, and compresses the clutch plate assembly. When the main pressure
falls, the diaphragm spring pushes the piston away from the clutch plate assembly, disengaging the clutch.

PLANETARY GEAR TRAINS

The planetary gear trains used on the ZF 6HP28 transmission comprise a single web planetary gear train and a double web
planetary gear train. These gear trains are known as Lepelletier type gear trains and together produce the six forward gears
and the one reverse gear.

Single Web Planetary Gear Train
The single web planetary gear train comprises:
Sunwheel
Three (naturally aspirated versions) or four (5.0L SC and 3.0L diesel versions) planetary gears Planetary gear carrier (spider)
Ring gear or annulus. Multiplate Drive or Brake Clutch – Typical www.JagDocs.com

solenoid valve in the valve housing directs hydraulic pressure to the lock cylinder, which moves the piston within the cylinder
and releases the park lock pawl at the rear of the transmission by means of a connecting rod. The solenoid on the lock cylinder
is energized and locks the cylinder piston in the unlocked position. Additional locking of the piston is achieved with ball
catches within the lock cylinder.

When park is selected, the solenoid on the lock cylinder is de-energized, the ball catches are released and the piston is free to
move in the lock cylinder. The solenoid in the valve housing is also de-energized. The spring loaded parking disc pulls the
cylinder piston in the park direction which allows the park disc to move on its mounting. This movement is transferred via the
connecting rod to parking pawl, which is engaged in the park lock gear.

If an electrical failure occurs, the park lock can be manually released by means of an emergency park release lever located in
the floor console. The lever is connected to the parking disc by a cable and allows the park lock to be released manually. For
additional information, refer to 307-05B Automatic Transmission/Transaxle External Controls.

TRANSMISSION CONTROL MODULE

The TCM is an integral part of the Mechatronic valve block which is located at the bottom of the transmission, within the fluid pan. The TCM is the main controlling component of the transmission.
The TCM processes signals from the transmission speed and temperature sensors, ECM and other vehicle systems. From the received signal inputs and pre-programmed data, the module calculates the correct gear, torque converter clutch setting and
optimum pressure settings for gear shift and lock-up clutch control.

DTC Description Possible Cause Action P0721-64
Output Shaft Speed Sensor
Circuit Range/Performance -
signal plausibility failure
Signal plausibility failure Clear DTC and test. If code re-detects suspect the
Transmission control module. Install a new
Transmission control module as required, refer to the
new module/component installation note at the top of
the DTC Index P0731-07
Incorrect Gear Ratio-
Mechanical Failures
Gear Ratio Monitoring.
Mechanical Failures Check and correct oil level. Clear DTC. If code
re-detects suspect Transmission (gearbox) internal
fault. Install a new Transmission as required, refer to
the new module/component installation note at the top of the DTC Index P0732-07
Incorrect Gear Ratio-
Mechanical Failures
Gear Ratio Monitoring.
Mechanical Failures Check and correct oil level. Clear DTC. If code
re-detects suspect Transmission (gearbox) internal
fault. Install a new Transmission as required, refer to
the new module/component installation note at the top of the DTC Index P0733-07
Incorrect Gear Ratio-
Mechanical Failures
Gear Ratio Monitoring.
Mechanical Failures Check and correct oil level. Clear DTC. If code
re-detects suspect Transmission (gearbox) internal
fault. Install a new Transmission as required, refer to
the new module/component installation note at the top of the DTC Index P0734-07
Incorrect Gear Ratio-
Mechanical Failures
Gear Ratio Monitoring.
Mechanical Failures Check and correct oil level. Clear DTC. If code
re-detects suspect Transmission (gearbox) internal
fault. Install a new Transmission as required, refer to
the new module/component installation note at the top of the DTC Index P0735-07
Incorrect Gear Ratio-
Mechanical Failures
Gear Ratio Monitoring.
Mechanical Failures Check and correct oil level. Clear DTC. If code
re-detects suspect Transmission (gearbox) internal
fault. Install a new Transmission as required, refer to
the new module/component installation note at the top of the DTC Index P0736-07
Incorrect Gear Ratio-
Mechanical Failures
Gear Ratio Monitoring.
Mechanical Failures Check and correct oil level. Clear DTC. If code
re-detects suspect Transmission (gearbox) internal
fault. Install a new Transmission as required, refer to
the new module/component installation note at the top of the DTC Index P0740-13 Torque Converter Clutch
Solenoid Circuit / Open -
Circuit Open
Pressure control solenoid
2 Circuit Open Circuit Clear DTC and test. If code re-detects suspect the
Transmission control module. Install a new
Transmission control module as required, refer to the
new module/component installation note at the top of
the DTC Index P0741-07 Torque Converter Clutch
Solenoid Circuit
Performance/Stuck Off -
Mechanical Failures
Too high slip at torque
converter clutch.
Mechanical Failures Suspect torque converter lockup clutch. Install a new
torque converter, refer to the new module/component
installation note at the top of the DTC Index. If
transmission fluid is in very poor condition and dirty,
install a new transmission, refer to the new
module/component installation note at the top of the
DTC Index P0745-04 Pressure Control Solenoid A
- System Internal Failures
System Internal Failures Suspect the Transmission control module. Install a
new Transmission control module as required, refer to
the new module/component installation note at the top of the DTC Index P0745-48 Pressure Control Solenoid A
- Supervision Software
Failure
Supervision Software
Failure Suspect the Transmission control module. Install a
new Transmission control module as required, refer to
the new module/component installation note at the top of the DTC Index P0758-12
Shift Solenoid B Electrical -
Circuit Short to Battery
Circuit Short to Power Suspect the Transmission control module. Install a
new Transmission control module as required, refer to
the new module/component installation note at the top of the DTC Index P0758-13
Shift Solenoid B Electrical -
Circuit Open
Solenoid valve 1 or
Pressure control Solenoid
G Circuit Open Circuit Suspect the Transmission control module. Install a
new Transmission control module as required, refer to
the new module/component installation note at the
top of the DTC Index P0771-71
Shift Solenoid E
Performance/Stuck Off -
actuator stuck
Actuator stuck Suspect the Transmission control module. Install a
new Transmission control module as required, refer to
the new module/component installation note at the top of the DTC Index P0775-04 Pressure Control Solenoid B
- System Internal Failures
System Internal Failures Suspect the Transmission control module. Install a
new Transmission control module as required, refer to
the new module/component installation note at the top of the DTC Index P0775-48 Pressure Control Solenoid B
- Supervision Software
Failure
Supervision Software
Failure Suspect the Transmission control module. Install a
new Transmission control module as required, refer to
the new module/component installation note at the top of the DTC Index

DTC Description Possible Cause Action P2722-48 Pressure Control Solenoid E
- Supervision Software
Failure
Pressure Control Solenoid
E supervision control
software failure Suspect the Transmission control module. Install a
new Transmission control module as required, refer to
the new module/component installation note at the
top of the DTC Index P2725-22
Pressure Control Solenoid E
Electrical - signal amplitude
> maximum
Pressure Control Solenoid
E Electrical signal
amplitude > maximum Suspect the Transmission control module. Install a
new Transmission control module as required, refer to
the new module/component installation note at the
top of the DTC Index P2725-1A
Pressure Control Solenoid E
Electrical - Circuit Resistance
Below Threshold
Pressure control solenoid
E electrical resistance
below threshold Suspect the Transmission control module. Install a
new Transmission control module as required, refer to
the new module/component installation note at the
top of the DTC Index P2725-1E
Pressure Control Solenoid E
Electrical - Circuit Resistance
Out Of Range
Pressure control solenoid
E circuit resistance out of
range Suspect the Transmission control module. Install a
new Transmission control module as required, refer to
the new module/component installation note at the
top of the DTC Index P2727-14
Pressure Control Solenoid E
Control Circuit / Open -
Circuit Short to Ground or
Open
Pressure Control Solenoid
E Control Circuit Short to
Ground or Open Circuit Suspect the Transmission control module. Install a
new Transmission control module as required, refer to
the new module/component installation note at the
top of the DTC Index P2729-11
Pressure Control Solenoid E
Control Circuit Low - Circuit
Short to Ground
Pressure control solenoid
E Circuit Short to Ground Suspect the Transmission control module. Install a
new Transmission control module as required, refer to
the new module/component installation note at the top of the DTC Index P2730-12
Pressure Control Solenoid E
Control Circuit High-Circuit
Short to Battery
Pressure control solenoid
E Circuit Short to Power Suspect the Transmission control module. Install a
new Transmission control module as required, refer to
the new module/component installation note at the top of the DTC Index P2731-04
Pressure Control Solenoid
F-System Internal Failures
Pressure Control Solenoid
F no sub type
information Suspect the Transmission control module. Install a
new Transmission control module as required, refer to
the new module/component installation note at the
top of the DTC Index P2731-48
Pressure Control Solenoid F -
Supervision Software Failure
Pressure Control Solenoid
F supervision software
failure Suspect the Transmission control module. Install a
new Transmission control module as required, refer to
the new module/component installation note at the
top of the DTC Index P2734-22
Pressure Control Solenoid F
Electrical-signal amplitude >
maximum
Pressure Control Solenoid
F Electrical signal
amplitude > maximum Suspect the Transmission control module. Install a
new Transmission control module as required, refer to
the new module/component installation note at the
top of the DTC Index P2734-1A
Pressure Control Solenoid F
Electrical-Circuit Resistance
Below Threshold
Pressure control solenoid
F electrical circuit
resistance below
threshold Suspect the Transmission control module. Install a
new Transmission control module as required, refer to
the new module/component installation note at the
top of the DTC Index P2734-1E
Pressure Control Solenoid F
Electrical-Circuit Resistance
Out Of Range
Pressure control solenoid
F electrical circuit
resistance out of range Suspect the Transmission control module. Install a
new Transmission control module as required, refer to
the new module/component installation note at the
top of the DTC Index P2736-14
Pressure Control Solenoid F
Control Circuit / Open -
Circuit Short to Ground or
Open
Pressure Control Solenoid
F Control Circuit Short to
Ground or Open Suspect the Transmission control module. Install a
new Transmission control module as required, refer to
the new module/component installation note at the
top of the DTC Index P2738-11
Pressure Control Solenoid F
Control Circuit Low - Circuit
Short to Ground
Pressure Control Solenoid
F Control Circuit Short to
Ground Suspect the Transmission control module. Install a
new Transmission control module as required, refer to
the new module/component installation note at the
top of the DTC Index P2739-12
Pressure Control Solenoid F
Control Circuit High - Circuit
Short to Battery
Pressure Control Solenoid
F Control Circuit Short to
Power Suspect the Transmission control module. Install a
new Transmission control module as required, refer to
the new module/component installation note at the
top of the DTC Index P2763-12 Torque Converter Clutch
Pressure Control Solenoid
Control Circuit High - Circuit
Short to Battery
Pressure control solenoid
F Circuit Short to Power Suspect the Transmission control module. Install a
new Transmission control module as required, refer to
the new module/component installation note at the top of the DTC Index

DTC Description Possible Cause Action P2764-11 Torque Converter Clutch
Pressure Control Solenoid
Control Circuit Low - Circuit
Short to Ground
Torque converter clutch
pressure control solenoid
control Circuit Short to
Ground Suspect the Transmission control module. Install a
new Transmission control module as required, refer to
the new module/component installation note at the
top of the DTC Index P2764-1A Torque Converter Clutch
Pressure Control Solenoid
Control Circuit Low-Circuit
Resistance Below Threshold
Torque converter clutch
pressure control solenoid
control circuit resistance
below threshold Suspect the Transmission control module. Install a
new Transmission control module as required, refer to
the new module/component installation note at the
top of the DTC Index P2764-1E Torque Converter Clutch
Pressure Control Solenoid
Control Circuit Low-Circuit
Resistance Out Of Range
Torque converter clutch
pressure control solenoid
control circuit resistance
out of range Suspect the Transmission control module. Install a
new Transmission control module as required, refer to
the new module/component installation note at the
top of the DTC Index P2807-11 Pressure Control Solenoid G
- Circuit Short to Ground
Park solenoid Circuit
Short to Ground Suspect the Transmission control module. Install a
new Transmission control module as required, refer to
the new module/component installation note at the top of the DTC Index P2807-12 Pressure Control Solenoid G
- Circuit Short to Battery
Park solenoid Circuit
Short to Power Suspect the Transmission control module. Install a
new Transmission control module as required, refer to
the new module/component installation note at the top of the DTC Index P2807-13 Pressure Control Solenoid G
- Circuit Open
Park solenoid Circuit
Open Circuit Suspect the Transmission control module. Install a
new Transmission control module as required, refer to
the new module/component installation note at the top of the DTC Index P2807-14 Pressure Control Solenoid G
- Circuit Short to Ground or
Open
Park solenoid Circuit
Short to Ground or Open
Circuit Carry out any diagnostic pinpoint tests associated
with this DTC using the manufacturer approved
diagnostic system. Suspect the Transmission control
module. Install a new Transmission control module as
required, refer to the new module/component
installation note at the top of the DTC Index B1087-82
LIN Bus "A" - alive /
sequence counter incorrect /
not updated
Alive counter fault Check Transmission Shift Module for stored DTCs.
Refer to the electrical Circuit diagrams and check
Transmission control module to Transmission Shift
Module for Short to Ground or Open Circuit (LIN Bus) B1087-83
LIN Bus "A" - value of signal
protection calculation
incorrect
Checksum error Check Transmission Shift Module for stored DTCs Refer
to the electrical Circuit diagrams and check
Transmission control module to Transmission Shift
Module for Short to Ground or Open Circuit (LIN Bus) B1087-87
LIN Bus "A" - missing
message
GSM is NOT visible to the
Transmission control
module on the LIN Bus Check Transmission Shift Module for stored DTCs Refer
to the electrical Circuit diagrams and check
Transmission control module to Transmission Shift
Module for Short or Open Circuit (LIN Bus) B1087-88 LIN Bus "A" - Bus off
LIN Bus Circuit fault.
Check hardware of LIN
connection between
transmission and GSM Refer to the electrical Circuit diagrams and check
Transmission control module to Transmission shift
module for Short, Open Circuit (LIN Bus). Check
Transmission Shift Module for related DTCs U0001-88
High Speed CAN
Communication Bus - Bus off
CAN Bus off Refer to the electrical Circuit diagrams and check CAN
Bus for Circuit fault U0100-82
Lost Communication With
Engine control module/PCM
"A" - alive / sequence
counter incorrect / not updated
Alive counter fault Check Engine control module for stored DTCs U0100-83
Lost Communication With
Engine control module/PCM
"A" - value of signal
protection calculation
incorrect
Checksum fault Check Engine control module for stored DTCs U0100-87
Lost Communication With
Engine control module/PCM
"A" - missing message
CAN Timeout
NOTE: Do NOT install a new Engine control
module if an Engine control module Timeout DTC is
only logged in the Transmission control module, the
failure is NOT with the Engine control module

Check Engine control module for stored DTCs. Check
CAN Bus Circuit for fault