Peterbilt 579 Leaf Spring Hanger Bracket (C11-6089)
Updated June 12, 2026
This leaf spring hanger bracket (also referred to as a spring hanger or suspension bracket) is a structural component that mounts the rear leaf spring to the frame of a 2018-2023 Peterbilt 579 equipped with a Paccar suspension. It serves as the pivot point for the spring assembly, allowing the spring to flex while maintaining proper axle position and ride height.
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How It Works
The hanger bracket bolts to the truck frame rail and provides a fixed mounting eye for the leaf spring. A spring bushing and pin connect the spring end to the bracket, permitting controlled vertical movement as the suspension absorbs road impacts. This part is typically used on tandem-axle configurations, supporting the rear leaf spring set.
Common Failure Symptoms
A worn or damaged hanger bracket can cause misalignment of the rear axle, uneven tire wear, sagging on one side, or a loud clunking noise when going over bumps. Visible cracks, rust-through, or elongated bolt holes are signs that the bracket has exceeded its service life and must be replaced to avoid suspension failure.
Installation Notes
Replacement requires lifting the vehicle and supporting the axle so the leaf spring is unloaded. The old bracket must be unbolted from the frame, and the spring bushing may need to be pressed out. New fasteners should be torqued to manufacturer specifications. Ensure the replacement bracket matches the original part number (C11-6089) for correct fitment on the Peterbilt 579 Paccar suspension.
