General Information

Transmission

• The 8-speed automatic transmission 0BK AWD is equipped with 8 hydraulically activated forward gears. When the torque converter lock-up clutch is closed, these forward gears become manually driven gears through bypassing the torque converter slip.
• A special feature of the 0BK transmission is the position of the front final drive (front axle differential with flange shafts) in front of the torque converter. This way an even distribution of the weight between the front and rear axles is attained.
• Refer to Self Study Program No 457; Audi A8 MY 2010 Drivetrain for more detailed information on the transmission function.

Torque Converter

The torque converter is equipped with a slip-controlled torque converter lock-up clutch. Due to the new design of this transmission, the torque converter is located behind the front final drive.

Mechatronic

The Mechatronic combines the following components as a complete synchronized unit:

• Transmission Control Module -J217- hydraulic control
• the sensors and actuators

The Mechatronic unit is installed in the transmission in the area of the ATF pan.

Transmission Control Module -J217-

The control module is a component of the Mechatronic in the transmission.

Determining the driving situation and driving resistance dependent shift point occurs automatically.

Advantages:

• Shifting depends on fuel consumption
• Maximum engine output is always available
• Individual adaptation of shift points in all driving situations
• Gear shift points are infinitely variable

Oil System for Transfer Case and Final Drive

Depending on the engine, there are transmissions that have either a separated or a combined oil system. Refer to OIL DISTRIBUTION .

For vehicles with combined oil systems the steps for it must be followed, because the oil level from the transfer case and the front axle differential are dependent on one another.

Shift Point Changes on Inclines and Declines

When driving on inclines or declines, gears are automatically selected using additional gear change maps. The selection is based on accelerator pedal position and the vehicle speed.

• The gear change map for extreme uphill stretches is matched to engine output.
• The gear change map for extreme downhill stretches is matched to the braking effect of the engine.
• By selecting a gear directly using tiptronic, the driver can use the engine braking effect with a specific gear engaged, for example when driving downhill with a trailer.