Dorman 540-903 Coil Spring Insulator - Front Upper

Dorman 540-903 Coil Spring Insulator

Dorman 540-903 is a front upper coil spring insulator made from rubber elastomer for specific Chevrolet and GMC applications. It is precision-engineered and tested to replace the original equipment part on supported vehicles, helping restore proper spring isolation and fit.

Key Features

• Rubber construction for durable spring-to-seat cushioning
• Round black insulator with a 143 mm outside diameter and 84 mm inside diameter
• Specific fit for front upper suspension locations
• Mounting hole attachment type for OE-style placement
• Thread diameter: 89 mm; thickness: 25 mm
• Cross-reference part numbers include Delphi TD4650W and MOOG K160045

Detailed Description

This coil spring insulator is built for front upper suspension use on a wide range of Chevrolet and GMC trucks, vans, and SUVs, including Chevrolet Astro, Chevrolet S10, Chevrolet Tahoe, GMC Safari, GMC Sonoma, and GMC Yukon applications. Dorman 540-903 helps maintain the interface between the coil spring and its mounting point, supporting proper seating and reducing direct metal-to-metal contact in the suspension assembly. The specific-fit design is intended for vehicles that require the listed dimensions and mounting style, including applications noted without locking tabs.

For buyers searching for a front upper coil spring insulator for Chevrolet Astro and GMC Safari, or a replacement coil spring insulator for Chevrolet S10, GMC Sonoma, and related GM platforms, this part number 540-903 provides an OE-style replacement option with the correct rubber material and round profile.

What It Helps Address

• Worn or cracked coil spring insulator material
• Noise caused by spring-to-seat contact
• Improper spring seating at the front upper mount
• Suspension vibration transferred through deteriorated rubber
• Fitment issues from a damaged OE insulator

Installation Notes

Verify the vehicle’s front upper suspension configuration before ordering, especially on Chevrolet S10, Chevrolet S10 Blazer, GMC Jimmy, and GMC Sonoma models with notes for applications without locking tabs. Match the listed dimensions, attachment type, and position to the original part before installation. This part is specific fit, so confirm year, make, model, and suspension layout against the vehicle application data.

Quality Assurance

Dorman designs this replacement coil spring insulator to match original equipment requirements for the listed vehicles and subjects it to testing for reliable service. Part number 540-903 is engineered as a direct replacement for supported Chevrolet and GMC front upper suspension applications.