MUD FLAPS & BRACKETS

Mud Flaps & Brackets For Peterbilt Trucks

Mud flaps are required by law on commercial trucks in most states and serve a real functional purpose — they deflect road debris, water, and tire spray away from following vehicles and protect the truck's frame, fuel tanks, and suspension components from stone damage. We carry rubber mud flaps, poly mud flaps, and mounting brackets for Peterbilt trucks in standard and custom sizes, along with replacement hardware for worn or broken mud flap hangers.

Frequently asked questions about mud flaps & brackets

Are mud flaps required by law on a Peterbilt truck?

Yes. FMCSA regulations require mud flaps or splash guards on commercial vehicles, and most states have additional requirements specifying minimum flap width, maximum ground clearance, and placement behind the rear-most axle. Many states also require mud flaps behind the steer axle on trucks over a certain weight. Specific requirements vary by state, so operators running interstate routes should verify compliance with the most restrictive state in their operating area.

What's the difference between rubber and poly mud flaps for a Peterbilt?

Rubber mud flaps are the traditional choice — flexible, heavy, and effective at absorbing and deflecting debris. They hold up well to cold temperatures but can become brittle with age. Poly (polyurethane or polyethylene) mud flaps are lighter, more resistant to cracking in extreme cold, and don't absorb moisture the way rubber can. Some poly flaps also offer better aerodynamic profiles for fuel economy, which has made them increasingly popular in fleet applications where weight and fuel savings matter.

How do I stop mud flap brackets from cracking or breaking on a Peterbilt?

Mud flap bracket failures are usually caused by stress concentration from running flaps that are too heavy for the bracket design, or from flaps that drag on the ground and transmit upward force into the bracket during dips and bumps. Using the correct bracket for your flap weight and ensuring the flap has adequate clearance from the ground at full suspension compression prevents most bracket failures. Stainless steel brackets are more resistant to fatigue cracking than painted mild steel, particularly in salt-belt states.

Other parts you might need

Shop fenders & liners for Peterbilt trucks