Automatic Gearbox BMW Z4 E89 18i 20i 28i Petrol N20 8632465 GA8HP45Z WARRANTY

Listing details

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

Automatic Gearbox BMW Z4 E89 18i 20i 28i Petrol N20 is a factory-original automatic transmission designed for BMW Z4 E89 models with the N20 engine. It offers precise, smooth gear shifts and full integration with the vehicle's drivetrain, electronics, and software. By maintaining the original specifications, it provides a reliable service solution for repairing or replacing a damaged gearbox.

Specifications and technical data

• SKU: 8632465
• Mark: BMW (Genuine OE)
• Condition: Used
• OEM Part Number: 8632465
• Substitutable numbers: 8632465, 24008632465, 8616004, 24008616004, 8601659, 24008601659, 8601662, 24008601662, 7643945, 24007643945, 7630579, 24007630579, 7642251, 24007642251, 7640274, 24007640274
• Fuel type: Petrol
• Gearbox type: Automatic
• Category: Automatic Transmission

Application and compatibility

The presented automatic transmission is designed for the BMW Z4 E89 generation roadster with N20 petrol engines in 18i, 20i, and 28i variants. The GA8HP45Z design was developed specifically for the torque characteristics of these units, ensuring consistent drivetrain performance and proper cooperation with factory engine management and driver assistance systems.

An automatic gearbox from this series is used in many BMW models; however, selection for a specific Z4 E89 unit should always be based on vehicle data and part numbers in the technical specification. This helps avoid issues with software, gear ratio, and accessory compatibility.

Technical characteristics of the GA8HP45Z transmission

GA8HP45Z is a modern, multi-speed automatic transmission designed to work with petrol engines. The applied design ensures:

• efficient torque transfer during dynamic driving,
• smooth gear shifting in comfort mode,
• seamless cooperation with the vehicle's electronic systems,
• the ability to use automatic and sequential modes (depending on the car's configuration).

Thanks to the factory configuration, this automatic gearbox maintains original shift points, which translates into predictable car behavior and compliance with factory driving mode settings.

Benefits of using an original BMW automatic gearbox

Choosing an original automatic transmission for the BMW Z4 E89 brings a number of practical service and utility advantages:

• Full structural fit – correct mounts, input shaft length, and drivetrain interface consistent with the factory design.
• Compatibility with electronics – proper cooperation with the transmission control module, engine ECU, and safety systems.
• Reproduction of factory shift characteristics – no need for software modifications when the correct reference is selected.
• Ability to utilize existing vehicle configuration – preservation of functions available in a given trim level.

Such a solution is particularly beneficial for post-accident repairs or after a transmission failure, when the priority is restoring factory operating parameters without experimenting with replacements of uncertain origin.

Condition, origin, and installation aspects

The offered gearbox comes from dismantling and is a used component, which allows for a significant reduction in repair costs compared to a new transmission while maintaining original BMW specifications. Before installation, a standard service procedure is recommended, including checking seals, verifying connection ports, and changing the oil and filter in accordance with the vehicle manufacturer's or a specialized automatic transmission workshop's recommendations.

Professional installation at a specialized service center is crucial to ensure proper transmission operation, correct system bleeding, oil level adjustment, and performing transmission adaptation in the vehicle's ECU, if required.

Technical support and selecting the right gearbox

When selecting this transmission for a specific BMW Z4 E89, it is worth paying attention to data from the vehicle card and information contained in the product's technical specification, including OEM part numbers and interchangeable numbers. This allows for confirmation of compatibility with the model year, engine version, and equipment configuration.

If you are planning a comprehensive repair or upgrade of the drivetrain area in your BMW and need other components from the same group, such as a torque converter, control elements, or additional transmission sub-assemblies, check the available parts in the BMW Automatic Gearboxes category.

For users who want to deepen their knowledge about transmission durability, common faults, and the principles of safely purchasing components from the secondary market, the following guide will be useful: Gearbox: manual, automatic, or DSG – common faults and a guide to buying a used gearbox. Thanks to it, you will more easily assess what to look for when choosing the right automatic gearbox for your BMW.