Full Cast Iron Brake Drums 3687X Class 8 Heavy Truck Brake Drums

Full Cast Brake Drum 3687X for Class 8 Trucks & Trailers | 16.5" x 7" Outboard Mount

Product Overview

The 3687X Brake Drum is a premium, high-performance solution for heavy-duty commercial vehicles requiring a 16.5" x 7" braking system. Engineered for outboard mount configurations, the 3687X is specifically designed to provide the strength of a full cast drum while maintaining an optimized weight to improve fuel efficiency and payload capacity.

Manufactured from high-carbon G3000 grey iron, our 3687X ensures superior thermal stability and rapid heat dissipation. It is an ideal choice for fleet operators who demand a balance between weight savings and the rugged durability needed for long-haul and vocational applications.

Technical Specifications

Vehicle Compatibility

The 3687X Brake Drum is widely used across North American heavy-duty truck brands and trailer axle systems:

Truck Brands: Freightliner, Kenworth, Peterbilt, International (Navistar), and Western Star.

Trailer Axles: Direct fit for Hendrickson, Meritor, and Dana axle configurations.

Axle Position: Primarily used on Drive and Trailer axles.

Cross-Reference & Interchange

This component is a direct replacement for the following industry references:

Gunite: 3687X, 3687

Webb: 66864F, 66884

Meritor: 53-123438-002, 123438

Dayton: 123438

Haldex: 3687X

Fleetrite: FLT3687X

Key Benefits

Optimized Weight-to-Strength Ratio: Engineered to be lighter than standard drums without sacrificing the structural integrity of a full cast iron design.

Superior Heat Sink: The high-carbon metallurgy absorbs and dissipates heat effectively, preventing "brake fade" and surface heat checking.

Precision Machined & Balanced: Every 3687X drum is dynamically balanced to eliminate wheel vibration and ensure smooth braking from day one.

Reduced Maintenance Costs: High wear resistance extends the service life of both the drum and the brake linings, keeping your trucks on the road longer.

FAQ

Q: What makes the 3687X different from the 3600AX?

A: While both are 16.5" x 7", the 3687X is typically designed to be slightly lighter while maintaining full-cast strength, making it popular for weight-sensitive trailer and truck applications.

Q: Can this drum be used on a steer axle?

A: No. The 3687X is designed for rear drive and trailer axles with a 7-inch width. Steer axles generally require narrower drums (e.g., 5-inch or 6-inch widths).

Q: Is it ready for installation out of the box?

A: Yes. Our drums come pre-balanced and are treated with a protective anti-rust coating. Just clean the friction surface before installation.