Structure of the automatic transmission

The dual-mass flywheel with the integrated centrifugal pendulum is securely connected with the combustion engine. The connection to the automatic transmission is performed via slip-on gearing.

The larger electrical machine and the additional torsional vibration damper mean that the housing of the GA8P75HZ automatic transmission is extended by 30 mm.

The hybridized scopes for the automatic transmission can be divided into the following components:

• Dual-mass flywheel
• Additional torsional vibration damper
• Decoupler
• Electric machine
• Reinforced multidisc clutch B (fixed brake)
• Electrical transmission oil pump for supply with transmission oil pressure when transmission input shaft is stationary (electric driving)

The multidisc clutch B is reinforced. This is necessary since it must also permit driving off and crawling of the vehicle in addition to its function as a shift element.

Fig 1: Identifying Automatic Transmission Components

Courtesy of BMW OF NORTH AMERICA, INC.

There is a separate functional description for the electrical machine.

The following schematic layout shows how the components are integrated in the automatic transmission.

Fig 2: Automatic Transmission Schematic Layout

Courtesy of BMW OF NORTH AMERICA, INC.

Overview, automatic transmission 

Fig 3: Overview Of Automatic Transmission

Courtesy of BMW OF NORTH AMERICA, INC.

The following table shows in which gear which shift element is closed.