Dorman 521-521 Suspension Control Arm and Ball Joint Assembly - Front Left Upper

Durable Suspension Control Arm and Ball Joint Assembly

The Dorman 521-521 suspension control arm and ball joint assembly is engineered for reliable performance in select Mercedes-Benz models. Designed with quality materials and pre-greased components, this assembly supports smooth suspension operation and vehicle handling.

• Pre-greased for immediate use without additional lubrication
• Includes rubber bushings and mounting hardware for a complete installation
• Aluminum control arm with a black finish for corrosion resistance
• Press-in ball joint with threaded stud for secure mounting
• Compatible with multiple Mercedes-Benz GL and ML series models

Product Features and Specifications

This suspension control arm and ball joint assembly features a forged aluminum control arm measuring up to 288.5 mm in width and 237 mm in length. The assembly includes a press-in ball joint with a 14 mm threaded stud and a 12.3 mm mounting hole diameter. Rubber bushings are integrated to reduce vibration and noise, while the included mounting hardware ensures a straightforward installation. The assembly is pre-greased, eliminating the need for additional lubrication during installation. This part is designed for light suspension grade applications and is not adjustable.

Compatible Mercedes-Benz Models

This Dorman 521-521 control arm and ball joint assembly is compatible with the following Mercedes-Benz vehicles: GL320, GL350, GL450, GL500, GL550, ML63 AMG, ML320, ML350, ML450, ML500, ML550, R63 AMG, R320, R350, and R500. It is engineered to meet the suspension requirements of these models, ensuring proper fit and function.

Common Suspension Issues Addressed

• Worn or damaged control arm bushings causing suspension noise or vibration
• Loose or failing ball joints affecting steering stability
• Corroded or weakened control arm compromising suspension integrity
• Uneven tire wear due to suspension misalignment
• Reduced handling performance and ride comfort

Installation Notes and Tips

Installation of the Dorman 521-521 assembly requires basic suspension knowledge and tools. Since the ball joint is pre-installed and press-fit, no additional ball joint assembly is necessary. Ensure all mounting hardware is securely tightened to manufacturer torque specifications. The pre-greased components reduce installation time, but verify lubrication points during routine maintenance. This part is not adjustable, so alignment should be checked after installation.

Quality Assurance and Warranty

Dorman suspension components are manufactured to meet or exceed OEM standards. The 521-521 assembly undergoes rigorous quality control to ensure durability and performance. While specific warranty details may vary, Dorman typically offers a limited warranty covering defects in materials and workmanship. Refer to Dorman’s official documentation for complete warranty information.