Audi A4 B8 A5 8T A6 C7 A7 4G S-Tronic Gearbox Output Shaft Gear 0B5311921A

Audi A4 B8 A5 8T A6 C7 A7 4G Gearbox Sprocket Shaft S-Tronic is a specialized component in the Automatic Transmission Parts category, designed for S‑Tronic dual-clutch systems in Audi vehicles. This solution is for users who want to restore proper gearbox operation while maintaining factory shifting characteristics.

Specifications and technical data

• SKU: 0B5311921A
• Mark: Audi
• Condition: Used
• OEM Part Number: 0B5311921A
• Substitutable numbers: 0B5311921A, 0B5 311 921 A
• Part type: Output Shaft
• Category: Automatic Transmission Parts

Purpose and Role in the S‑Tronic Gearbox

The presented sprocket shaft operates in a critical area of the S‑Tronic gearbox, responsible for precise torque transfer and cooperation with other elements of the planetary gear set and intermediate shafts. The proper condition of this component directly impacts:

• smooth gear changes in automatic and manual modes,
• gearbox operational stability during dynamic acceleration,
• reduction of noise and vibrations generated by the gearbox.

By maintaining geometry consistent with the factory solution, the component allows the gearbox to operate according to the manufacturer's specifications.

Benefits of Using an Original Audi Component

The OEM version of the S‑Tronic gearbox sprocket shaft offers several practical advantages compared to low-quality aftermarket alternatives. Key benefits include:

• factory fit for transmissions used in Audi A4 B8, A5 8T, A6 C7, and A7 4G,
• proper cooperation with clutch baskets and other shafts,
• appropriate hardness and tooth treatment, promoting even wear and stable operation,
• compatibility with the factory gearbox control unit software, without the need for parameter modifications.

Choosing an original component is particularly important for dual-clutch transmissions, where fitting tolerances and manufacturing precision directly affect the durability of the entire system.

Condition, Verification, and Preparation for Installation

The component is a used part from a dismantled vehicle, offered for an economical repair while maintaining an OEM-class component. Before being offered, the sprocket shaft is verified for:

• condition of the tooth surfaces (no chipping or excessive wear),
• shaft straightness and absence of visible mechanical damage,
• condition of surfaces cooperating with bearings and other gearbox elements.

A component prepared in this way provides a solid foundation for professional gearbox refurbishment or repair at a specialized service center.

Practical Application in Service

The S‑Tronic gearbox sprocket shaft is used for both comprehensive gearbox rebuilds and repairs targeting specific symptoms, such as:

• jerking when starting off or changing gears under load,
• unusual noises from inside the gearbox at specific speed ranges,
• uneven power delivery felt through the steering wheel or body.

Selecting the correct part based on the part number and gearbox type helps reduce the risk of repeat gearbox disassembly and speeds up the service process.

More Parts and Knowledge about Audi Automatic Transmissions

If you are looking for other Audi Automatic Transmission Parts, check out our dedicated offer: Audi Automatic Transmission Parts. There you will find a wide selection of components for S‑Tronic and other automatic transmissions from this brand.

Before purchasing a used transmission component, it is advisable to expand your knowledge about common faults and methods for verifying the gearbox's condition. Practical information can be found in the article: Gearbox: Manual, Automatic, or DSG – Common Faults and a Guide to Buying a Used Gearbox, which will help you better plan repairs and select appropriate components.