Dorman 521-397 Suspension Control Arm - Rear Left Lower

Durable Suspension Control Arm for BMW 525i, 528i, 530i, 540i

The Dorman 521-397 suspension control arm is engineered to provide reliable performance and precise handling for select BMW models. Designed with quality materials and construction, this control arm is a direct replacement part that helps maintain your vehicle's suspension integrity.

• Constructed from lightweight aluminum with a coated black finish for corrosion resistance
• Includes a rubber bushing with a black color and precise dimensions (14.3 mm inside diameter, 39.6 mm outside diameter, 92 mm length)
• Overall length of 262.5 mm ensures proper fitment and alignment
• Features a welded ball joint mounting type with a threaded stud (ball joint not included)
• Press-in end type with bushing linkage end for secure installation
• Regular grade type, non-adjustable design for consistent suspension geometry

This suspension control arm is crafted using a casting and forging process to balance strength and durability while minimizing weight. The aluminum material offers corrosion resistance and contributes to improved vehicle handling. The included rubber bushing helps absorb road vibrations and reduce noise, enhancing ride comfort. Although the ball joint is not included, the welded mounting design allows for easy installation of compatible ball joints. The black coated finish protects the arm from environmental wear, extending its service life.

Compatible Vehicles and Applications

This Dorman suspension control arm is compatible with BMW 525i, 528i, 530i, and 540i models. It is designed to replace the original equipment part, restoring proper suspension function and alignment. The part number 521-397 ensures you receive the correct component for these specific BMW vehicles.

Common Suspension Issues Addressed

• Worn or damaged control arm bushings causing steering instability
• Corroded or bent control arms affecting wheel alignment
• Excessive vibration or noise from suspension components
• Loose or failing ball joint mounts (ball joint replacement required separately)
• Uneven tire wear due to suspension misalignment

Installation Notes and Tips

• Ensure vehicle is securely lifted and supported before removal
• Remove old control arm and inspect ball joint and mounting hardware
• Replace bushings if worn or damaged; note that ball joint is not included with this part
• Torque all fasteners to manufacturer specifications for safety and performance
• Wheel alignment is recommended after installation to maintain proper handling

Quality Assurance and Warranty

Dorman suspension control arms are manufactured to meet or exceed OEM standards for fit, form, and function. The 521-397 part undergoes rigorous quality checks to ensure durability and reliability. While specific warranty details may vary, Dorman typically offers a limited warranty covering defects in materials and workmanship to provide confidence in your purchase.