Dorman 521-301 Suspension Control Arm and Ball Joint Assembly - Front Left Upper

Overview of Dorman Suspension Control Arm and Ball Joint Assembly

The Dorman 521-301 suspension control arm and ball joint assembly is designed specifically for Mercedes-Benz S430 and S500 models. This pre-greased, iron control arm assembly offers a reliable replacement solution for light suspension grade applications, ensuring proper vehicle handling and suspension performance.

• Pre-greased for immediate installation
• Includes rubber bushings and mounting hardware
• Press-in ball joint with threaded stud
• Constructed from durable iron with a black finish
• Compatible with Mercedes-Benz S430 and S500 models

Detailed Product Description

This Dorman suspension control arm and ball joint assembly (part number 521-301) features a casting/forged iron control arm designed for light suspension grade use. The assembly comes pre-greased, eliminating the need for additional lubrication during installation. It includes rubber bushings to help absorb road vibrations and reduce noise, along with all necessary mounting hardware for a straightforward replacement process. The ball joint is press-in mounted and comes installed with a threaded stud, providing secure attachment and reliable steering control. The control arm measures a maximum length of 237 mm and a maximum width of 288.5 mm, with a mounting hole diameter of 12.3 mm, ensuring precise fitment for the specified Mercedes-Benz models.

Compatible Vehicles and Applications

This suspension control arm and ball joint assembly is compatible with the following Mercedes-Benz vehicles:

• Mercedes-Benz S430
• Mercedes-Benz S500

It is designed to replace worn or damaged control arms and ball joints, restoring proper suspension geometry and improving vehicle stability.

Common Issues Addressed by This Assembly

• Excessive suspension noise or clunking
• Uneven tire wear due to misalignment
• Loose or unstable steering feel
• Vibration or shaking during driving
• Worn or damaged control arm bushings and ball joints

Installation Notes and Tips

Installation of the Dorman 521-301 control arm and ball joint assembly should be performed by a qualified technician. Since the ball joint is pre-installed and the assembly is pre-greased, no additional lubrication is required. Ensure all mounting hardware is securely tightened to manufacturer specifications. Verify alignment after installation to maintain proper suspension geometry and tire wear.

Quality Assurance and Warranty

Dorman suspension components are manufactured to meet or exceed OEM standards for fit, form, and function. This control arm and ball joint assembly undergoes rigorous quality checks to ensure durability and performance. While specific warranty details may vary, Dorman typically offers a limited warranty covering defects in materials and workmanship.