BMW E39 520i E46 320i Z4 E85 2.2i M54 Automatic Gearbox 1423928 A5S325Z WARRANTY

BMW E39 520i E46 320i Z4 E85 2.2i M54 Automatic Gearbox is a factory-spec Automatic transmission assembly, designed to work with the original BMW drivetrain. This product belongs to the Automatic gearboxes category and is suitable for users looking for a complete, structurally compatible solution instead of costly refurbishment.

Specifications and technical data

• SKU: 1423929
• Mark: BMW (Genuine OE)
• Condition: Used
• OEM Part Number: 1423928
• Substitutable numbers: 24001423929, 1423929, 24001423928, 1423928
• Gearbox type: Automatic
• Category: Automatic Transmission

Application and compatibility with BMW models

The described automatic gearbox has been designed to work with the M54 engine unit in popular BMW models: 5 Series E39 520i, 3 Series E46 320i, and the Z4 E85 2.2i roadster. By maintaining the factory drivetrain configuration, it ensures consistent operation with the engine, driveshaft, and vehicle electronics, which facilitates installation in place of a worn-out transmission.

Choosing a complete gearbox from the same design family helps reduce the risk of fitment issues, such as differences in gear ratios, mounts, or control systems, which is particularly important in the case of BMW automatic transmissions.

Technical characteristics of the automatic transmission

The presented unit belongs to the Automatic gearboxes category, which means an integrated transmission system with hydraulic gear shift control and cooperation with the vehicle's electronic control unit. The Automatic design ensures smooth gear shifting, stable torque transfer, and comfortable operation under typical road conditions.

An automatic gearbox of this type is particularly valued in BMW models with the M54 engine for its predictable gear shifting characteristics, good cooperation with the traction control system, and the ability to effectively utilize the engine's RPM range in daily use.

Benefits of choosing an original used BMW gearbox

By choosing an original, used BMW automatic gearbox, you receive a component factory-designed for a specific drivetrain configuration, which translates into proper fitment with mounts, half-shafts, and the control system. This type of solution is often more predictable than transmissions that have undergone deep modification or uncertain refurbishment.

A used gearbox with the manufacturer's specifications preserved also allows you to maintain driving characteristics consistent with the assumptions of BMW engineers – from the way gears shift, through the reaction to load, to the cooperation with automatic operating modes (e.g., calm or dynamic driving). This is particularly important for drivers who expect consistent vehicle behavior after drivetrain repairs.

Practical installation and maintenance tips

Before installation, it is recommended to verify the compatibility of the gearbox with the specific engine version and model year of the vehicle, as well as to prepare the transmission oil cooling system and check the condition of the mounting bushings. Professional installation of the automatic gearbox, along with an oil and filter change (if the design provides for it), significantly affects the refinement and durability of the entire drivetrain.

For workshops and users planning a transmission replacement, information on when it is worth opting for an original used gearbox instead of investing in a costly repair may be useful. This topic is discussed in more detail in the article: Manual gearbox failures and choosing an original used transmission, which helps to understand the economic and technical aspects of such a decision.

Expanding repairs within the BMW drivetrain

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 additional transmissions, control elements, or related components, check out the available parts in the BMW automatic gearboxes category.

In situations where the vehicle's downtime in the workshop is a concern, it is also worth reading the material describing the impact of parts availability on repair speed – you can find more on this topic in the article: how the availability of used OEM parts shortens repair time in the workshop.