Transmission BMW M5 F90, GA8HP75Z

BMW M5 F90 (2017–2023) utilizes the GA8HP75Z (also commonly referred to as the M Steptronic with Drivelogic). This marked a significant shift in M5 history, as it replaced the 7-speed Dual Clutch Transmission (DCT) found in the previous F10 generation with a high-performance version of the ZF 8-speed torque-converter automatic.

Below are the technical specifications and business-critical details for this transmission:

1. Technical Specifications

The “Z” in GA8HP75Z typically denotes the ZF-manufactured version for BMW.

• Manufacturer: ZF Friedrichshafen.

   

• Type: 8-Speed Automatic (Torque Converter).

   

• Torque Rating: Officially rated for up to 750 Nm ($approx$ 553 lb-ft) of torque in stock form, though it is known to handle more in Competition and CS trims.

   

• Drivelogic: Features three distinct shift modes (Efficient, Sport, and Track) that adjust shift speed and ferocity.

• Weight: Approximately 84–86 kg (including oil).

   

2. Gear Ratios

The closely stacked ratios allow the S63 V8 engine to stay within its optimal power band:

3. Key Differentiators (M-Specific)

Unlike the standard 8HP75 found in a 540i or M550i, the M5 version includes:

• Reinforced Internal Clutches: To manage the violent shifts and high torque of the S63 engine.

   

• M-Specific Software: Calibrated for lightning-fast downshifts and “shift-point” memory.

• Integration with M xDrive: The transmission works in tandem with the transfer case to manage the 4WD, 4WD Sport, and 2WD (Pure RWD) modes.

4. Sourcing & Identification

If you are sourcing this for inventory or a client, note the following:

• Bellhousing: It uses the N63/S63 V8 bolt pattern (the “Big Bellhousing”). It will not bolt onto B58 or N57 inline engines without an adapter.

   

• Output Flange: Typically uses a light “tripod” flange for a flexible Guibo/Hardy coupling.

• Cooling: Features a high-capacity heat exchanger often bolted directly to the unit to manage the heat generated during track use.

• Compatibility: While the hardware is similar to the M8 (F91/F92/F93) and X5M/X6M (F95/F96), the mechatronics and software are specific to the F90 chassis.

Note for Business: Used units from 2018–2020 models are common in the aftermarket, but 2021+ (LCI) units may have slight mechatronic variations. Always verify the specific ZF 10-digit part number on the transmission nameplate for exact mapping.