Audi Q7 363 User Manual
Service Training
Audi Q7 - Power Transmission / Transfer Case 0AQ
Self-Study Programme 363
Audi Q7 - Power transmission by the inventor of the quattro®.
The powertrain concept of the Audi Q7 offers impressive performance at high speeds in addition to outstanding dynamics, both on and off the road.
The permanent quattro four-wheel drive® with asymmetric, dynamic torque split ensures maximum traction
and cornering stability. These features are essential to good driving dynamics and active motoring safety, particularly when driving on paved roads and at high speeds.
The newly developed transfer case 0AQ is the centrepiece of the power transmission system.
This SSP deals mainly with the design and function of this new development.
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Contents
Introduction
Drive concept . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
Subassemblies overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Brief description of the gearbox
6-speed manual gearbox 08D . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
6-speed automatic gearbox 0AT / 09D . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Gear selector mechanism
Automatic gearbox selector mechanism . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Manual gearbox selector mechanism (refer to SSP 299) . . . . . . . . . . . . . . . . . . . . .
Transfer case 0AQ
Design / function of transfer case 0AQ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
Self-locking centre differential. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
Components overview / design / function . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
Asymmetric basic torque distribution . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
Asymmetric/dynamic torque distribution . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
Chain drive . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
Lubrication . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
Oil supply / sealing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
Service
Service / special tools . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
Useful information
Operating instructions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
This self-study programme teaches the design and function of new vehicle models, new automotive components or new technologies.
The self-study programme is not a workshop manual!
All values given are intended as a guideline only, and refer
to the software version valid at the time of publication of the SSP.
Please refer to the relevant service literature for current inspection, adjustment and repair instructions.
NoteReference
Introduction
Drive concept
As an SUV* with excellent on- and off-road
driving dynamics, the Q7 is equipped as standard
with quattro four-wheel drive.
The running gear and the layout of the drive train
sub-assemblies were adopted from the VW Touareg.
This configuration allows the engine to be positioned directly over the front axle. Thus, the step-up
gear and the transfer case migrate more towards the
centre of the vehicle, favouring a well-balanced axle
load distribution beneficial to driving dynamics.
Rear axle differential 0AB
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The sub-assemblies step-up gear, front axle differential and transfer case are independent components. The powertrain has what is known as a
"modular design".
The advantage of this modular design is that it enables the ground clearance of an off-road vehicle to
be increased.
* SUV = sport utility vehicle
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One of the primary development goals for the Audi
Q7 was good driving dynamics on paved roads.
A special reduction gear and a mechanical differential lock were dispensed with in favour of the redesigned transfer case and the newly developed selflocking centre differential.
The self-locking centre differential is already in use
in the Audi RS4 and S4, and features asymmetric/
dynamic torque distribution.
Transfer case 0AQ
Up to 85% of driving torque can be transferred
mechanically, i.e. without EDL engagement, to the
rear axle and up to 65% to the front axle. The new
differential ensures optimal on-road driving dynamics.
When wheelspin occurs - off road or on icy surfaces
- the EDL control system engages and provides traction in almost any driving situation.
Step-up gear
Automatic or manual
gearbox
Front axle differential 0AA
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Introduction
Sub-assemblies overview
The following gearboxes are used:
Audi Q7 4.2 FSI:
257 kW (350 bhp), 440 Nm
Audi Q7 3.0 TDI:
171 kW (233 bhp), 500 Nm
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Audi Q7 3.6 FSI:
206 kW (280 bhp, 360 Nm)
6-speed automatic gearbox 0AT
(expected SOP: 4th quarter 2006)
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6-speed automatic gearbox 09D
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6-speed manual gearbox 08D/ ML400
(expected SOP: 2nd quarter 2006)
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The front and rear axle differentials derive from the
VW Touareg. Both differentials are manufactured by
ZF Getriebe GmbH.
Front axle differential 0AA
The left-hand drive flange shaft has been extended
to compensate for the asymmetric installed position
of the front axle differential.
Thus, the additional torque resultant from the drive
torque is transmitted symmetrically to the front
axle. Negative effects on steering are thus eliminated.
Rear axle differential 0AB
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Transfer case 0AQ was redesigned for use in the
Audi Q7.
The 0AQ transfer case was developed in conjunction
with, and is manufactured by Borgwarner.
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Brief description of the gearbox
6-speed manual gearbox 08D...
… is a conventional full synchromesh
countershaft-type gearbox, also known as a "3-shaft
gearbox".
…derives from the VW Touareg, in which it has
already proved successful.
… is used for engines with up to 400 Nm of torque.
The 08D gearbox was developed by, and is manufactured by ZF- Getriebe GmbH.
The 1st and 2nd gears are selected using a triplecone synchroniser.
The 3rd, 4th and reverse gears have a double-cone
synchroniser.
The 5th and 6th gears have a single-cone synchroniser.
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Reference
For further information on the
08D gearbox, please refer to SSP 299.
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The 6-speed automatic gearbox 0AT...
… is an electro-hydraulically controlled 6-speed
planetary gearbox (multi-step automatic gearbox)
with hydrodynamic torque converter and slip-controlled converter lockup clutch.
The hydraulic control unit (valve body) and the electronic control unit have been combined in a unit,
the so-called mechatronics. The mechatronics are
located in the oil sump.
The 0AT gearbox...
…is a new development for the Audi Q7 optimised
with regard to weight and fuel economy for engines
with up to 400 Nm of torque.
… belongs to the same family as the 6-speed automatic gearboxes 09E and 09L
The 0AT gearbox was developed by, and is manufactured by ZF- Getriebe GmbH.
Other features:
– Special deep-seated ATF intake point and the
large ATF capacity to ensure proper oil intake
during off-road use.
– Extended gearbox breather pipe to prevent
ingress of water into the gearbox even under
adverse conditions.
– Large-sized torque converter and torque con-
verter lock-up clutch.
– Integration of the gearbox into the immobiliser
system
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Reference
For further information on 6-speed
automatic gearboxes 09E and 09L, please refer
to SSPs 283/284 and SSP 325.
Note
This gearbox will not be available at roll-out.
Further details will be published later in a separate SSP.
9
Gearbox code
6-speed automatic gearbox 09D…
… is a conventional electro-hydraulically controlled 6speed planetary gearbox (multi-step automatic gearbox) with hydrodynamic torque converter and slipcontrolled converter lockup clutch.
The hydraulic control unit (valve body) is located in
the oil sump, while the electronic control unit is
accommodated externally in the vehicle interior
(under the right-hand front seat).
The 09D gearbox...
…derives from the VW Touareg, in which it has
already proved successful.
… is used for engines with up to 750 Nm of torque.
… belongs to the same family as the 6-speed automatic gearbox 09G (see SSP 291)
The 09D gearbox was developed by, and is manufactured by Japanese gearbox manufacturer AISIN AW
CO., LTD.
Other features:
– Special deep-seated ATF intake point and the
large ATF capacity to ensure proper oil intake
during off-road use.
– Extended gearbox breather pipe to prevent
ingress of water into the gearbox even under
adverse conditions.
– Large-sized torque converter and torque con-
verter lock-up clutch.
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Reference
For further information on 6-speed
automatic
gearbox 09G, please refer to SSP 291.
Gear selector mechanism
Automatic gearbox selector mechanism
The design and function of the gear selector mechanism in the Q7 are largely identical to that of the
gear selector mechanism used in the Audi A6`05.
The differences the gear selector mechanism used
in the Audi A6`05 are listed below.
The gear selector mechanism can be removed vehicle interior for repairs (e.g. to replace microswitch
F305).
When the gear selector mechanism is replaced, the
selector housing (installed from the exterior)
remains installed in the vehicle. Only the gear selector mechanism function unit need be replaced.
Selector lever position indicator unit Y26
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Gear selector mechanism function unit
Connector B
(4 pin to vehicle wiring loom/gearbox)
Funnel/guide
The funnel makes it easier to
emergency-release the P-lock
Connector housing
Connector A
(10-pin to vehicle wiring loom/ gearbox)
Selector lever sensors
control unit J587 with
tiptronic switch F189
Connector C (10-pin
to display unit Y26)
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Reference
For further information on the
gear selector mechanism used in the Audi
A6’05, please refer to SSPs 325 and 283.
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