BMW 1 2 3 4 Series F20 F21 F22 F30 F31 F32 Rear Axle Subframe Carrier 6863637

The BMW F20 F21 F30 F31 Subframe Cradle Carrier is a component from the longitudinal body frame parts and brackets category, designed for the rear suspension of selected BMW 1 and 3 Series models. It serves as a robust mounting base for rear suspension components, influencing handling stability, wheel geometry, and the vehicle's structural safety.

Specifications and technical data

• SKU: 6863637
• Mark: BMW (Genuine OE)
• Condition: Used
• OEM Part Number: 6863637
• Substitutable numbers: 33316792505, 6792505, 33316797503, 6797503, 6863637
• Location on the vehicle: Rear
• Category: Frame Rails & Subframes

Purpose and Function in the Vehicle

The rear subframe / cradle in BMW F20, F21, F30, and F31 models acts as a load-bearing structure for key suspension and drivetrain elements at the rear of the car. It is responsible for:

• stable mounting of control arms, hubs, and other rear suspension components,
• maintaining correct wheel geometry in terms of toe and camber,
• transferring loads from the road surface to the body in a controlled and predictable manner,
• preserving the structural rigidity of the rear body frame.

Its placement at the rear of the vehicle means this component directly impacts the car's handling, especially during braking, acceleration, and driving over uneven surfaces.

Construction and Technical Characteristics

The rear cradle for this BMW series is designed as a rigid, multi-point bracket that integrates with the longitudinal body frame parts. The construction includes:

• precisely positioned mounting points to the body, ensuring adequate stiffness and resistance to torsion,
• defined mounting locations for suspension elements, facilitating the maintenance of factory settings,
• compatibility with original BMW solutions for rear suspension on the F20/F21/F30/F31 platforms.

As a component within the longitudinal body frame parts and brackets group, the cradle works in conjunction with other structural elements to form a cohesive load-bearing system for the rear axle.

Benefits of Using an Original BMW Cradle

Using an original rear cradle in the BMW F20/F21/F30/F31 series allows for the preservation of the driving parameters intended by the manufacturer. Key advantages include:

• factory fitment to body and suspension mounting points,
• maintaining predictable vehicle behavior under heavy loads and dynamic driving,
• compatibility with safety systems (ABS, ESP, stability control systems) which rely on correct axle geometry,
• easier diagnostics and servicing of the suspension due to the preservation of the original design.

This solution is particularly recommended for accident repairs, replacement of corroded load-bearing elements, or restoring the vehicle to its original factory specifications.

Condition, Verification, and Service Application

The item is offered as a used part, allowing for economical repairs while maintaining the original BMW construction. Such components are often chosen by marque-specialist workshops when it is necessary to:

• restore rear axle geometry after mechanical damage or collision,
• limit repair costs while retaining OEM-grade parts,
• prepare the vehicle for wheel alignment after suspension component replacement.

Prior to installation, standard workshop inspection and comparison with the removed part for structural compatibility are recommended.

Related Categories and Technical Knowledge

If you are looking for other items in the BMW Longitudinal Body Frame Parts and Brackets category, check out the available BMW longitudinal body frame parts and brackets in our store to select complete structural solutions for your model.

For major repairs to the running gear and drivetrain, it is also worth considering the condition of the clutch and drivetrain components. The guide article Clutch and Dual-Mass Flywheel – Diagnostics and Part Selection for the Drivetrain may be helpful in planning comprehensive service work on vehicles with single or multi-axle drive.