Raybestos 982121R Disc Brake Rotor - Front

Overview of Raybestos R-Line Disc Brake Rotor 982121R

The Raybestos R-Line Disc Brake Rotor 982121R is engineered for reliable braking performance on select Mercedes-Benz models. Designed as a vented, conventional rotor, it offers consistent heat dissipation and durability for vehicles like the GL350, GL450, and ML350.

• Compatible with Mercedes-Benz GL350, GL450, GLE400, GLS350d, GLS450, ML350, and ML400
• Part number 982121R ensures precise fitment and quality
• Vented disc brake rotor design for improved cooling
• Overall height: 2.146 inches (54.5 mm)
• Outside diameter: 13.780 inches (350 mm)
• Mounting bolt hole quantity: 5 with 0.600 inch (15.25 mm) diameter holes
• Center hole diameter: 2.638 inches (67 mm)
• Smooth surface type for consistent pad contact
• Nominal thickness: 1.260 inches (32 mm) with discard thickness at 1.158 inches (29.4 mm)

Detailed Product Description

The Raybestos R-Line 982121R disc brake rotor is a vented, conventional rotor designed to meet the braking demands of various Mercedes-Benz SUVs and crossovers. Its vented construction allows for enhanced heat dissipation during braking, reducing the risk of brake fade under heavy use. The rotor features a smooth surface type that promotes even brake pad wear and consistent stopping power. With an outside diameter of 13.780 inches (350 mm) and an overall height of 2.146 inches (54.5 mm), this rotor fits vehicles requiring a 5-bolt mounting pattern with a 4.409 inch (112 mm) bolt circle diameter. The nominal thickness of 1.260 inches (32 mm) ensures structural integrity, while the discard thickness of 1.158 inches (29.4 mm) indicates when replacement is necessary to maintain safe braking performance.

About the Raybestos R-Line Product Line

The R-Line by Raybestos is a product line focused on delivering reliable, OE-quality brake components for a range of vehicles. This line emphasizes precise fitment and consistent performance, making it suitable for drivers who require dependable braking without extensive modifications. The 982121R rotor exemplifies the R-Line’s commitment to quality through its vented design and adherence to strict dimensional specifications.

Common Applications and Problem Solving

• Replacement for worn or warped rotors on Mercedes-Benz GL350, GL450, GLE400, GLS350d, GLS450, ML350, and ML400
• Addresses brake noise and vibration caused by uneven rotor surfaces
• Improves braking consistency by restoring proper rotor thickness and surface smoothness
• Helps prevent brake fade during extended or heavy braking conditions
• Resolves fitment issues related to bolt hole pattern and rotor dimensions

Installation Notes and Tips

• Verify rotor thickness before installation; replace if below discard thickness of 1.158 inches (29.4 mm)
• Ensure mounting surfaces and bolt holes are clean and free of debris
• Torque mounting bolts to manufacturer specifications to avoid rotor warping
• Inspect brake pads for wear and replace if necessary to ensure optimal rotor performance
• Perform a bed-in procedure after installation to maximize braking efficiency

Quality Assurance and Warranty

Raybestos R-Line rotors, including part number 982121R, are manufactured to meet or exceed OEM specifications for fit, form, and function. The vented rotor design and precise machining contribute to consistent braking performance. While specific warranty details may vary, Raybestos products typically come with a limited warranty against defects in materials and workmanship, providing confidence in product reliability.