BMW F20 F21 M135i F13 640i N55 Automatic Gearbox 8638262 GA8HP45 ZAJ WARRANTY

Listing details

The gearboxes are sold with a 90-day warranty! They were tested before removal and are in full working order.

BMW F20 F21 M135i F13 640i N55 Automatic Gearbox is a factory-original component from the GA8HP45 family, designed for vehicles with a petrol powertrain. This is a used, fully original automatic transmission, providing an effective solution for drivetrain repairs or professional replacement of a damaged gearbox.

Specifications and technical data

• SKU: 8638262
• Mark: BMW (Genuine OE)
• Condition: Used
• OEM Part Number: 8638262
• Substitutable numbers: 8638262, 24008638262, 9487554, 24009487554, 8486824, 24008486824, 8684716, 24008684716, 8678717, 24008678717, 8623599, 24008623599, 8645366, 24008645366, 8601213, 24008601213, 8601185, 24008601185, 8681088, 24008681088
• Fuel type: Petrol
• Gearbox type: Automatic
• Category: Automatic Transmission

Purpose and compatibility

The presented gearbox belongs to the Automatic transmissions category and has been designed to work with the N55 engine in BMW 1 Series F20/F21 M135i and 6 Series F13 640i models. The GA8HP45 design is optimized for the high torque of the petrol unit, ensuring smooth power delivery and stable operation across a wide range of loads.

This type of automatic transmission is particularly valued in high-demand road applications, where precise gear shifting, driving comfort, and predictable drivetrain behavior during dynamic acceleration are essential.

Technical and functional characteristics

The GA8HP45 gearbox is a modern, multi-speed automatic transmission adapted to work with a petrol fuel system. The applied design enables:

• efficient gear ratio matching to the characteristics of the N55 engine,
• reduction of energy losses in the drivetrain,
• stable operation in both comfort and dynamic modes,
• maintenance of proper operating refinement during load changes.

The automatic transmission type allows for integration with factory vehicle control systems, which facilitates configuration and restoration of full functionality after replacing a damaged unit.

Application in service practice

This used BMW automatic transmission is a good choice for repairs where maintaining the original manufacturer's specifications is crucial. It allows for:

• cost reduction compared to purchasing a new transmission,
• maintaining factory drivetrain performance parameters,
• preserving compatibility with existing control installations and equipment.

Before installation, a standard service procedure is recommended, including checking the oil level, seals, and updating the control software in accordance with BMW guidelines to fully utilize the capabilities of this gearbox.

VIN/OEM selection and technical support

Due to the specific nature of BMW automatic transmissions, the selection of the appropriate unit should be based on vehicle data, such as the VIN and OEM part numbers and interchangeable numbers. This helps avoid discrepancies in gear ratios, control systems, and mountings, and speeds up the installation process in the vehicle.

If you want to better understand how to safely choose used gearboxes and what to look for when verifying OEM numbers and installation procedures, check out the guide Why it is worth buying used gearboxes and engines – facts instead of myths, which discusses the practical aspects of selecting and operating such components.

BMW drivetrain expansion

If you are planning a comprehensive repair or upgrade of the drivetrain area in your BMW and need other elements from the same group, such as a torque converter, additional automatic transmissions, or compatible control modules, check the available parts in the BMW automatic transmissions category.