Frequently Asked Questions About Peterbilt 375/377 Mud Flaps

What are the exact mounting hole patterns for Peterbilt 375/377 mud flaps?

Peterbilt 375/377 mud flaps typically use a standard 2.5-inch center-to-center bolt pattern for the top mounting brackets. The bracket width is usually 24 inches for standard applications, though some wider configurations may require 30-inch brackets. Always verify your specific truck's measurements before ordering, as some model years between 1987-2007 may have slight variations in mounting points.

Will these mud flaps fit both single and dual rear wheel configurations?

Yes, but you'll need different sizes. Single rear wheel setups typically require 24-inch wide mud flaps, while dual rear wheel configurations need 30-inch or 36-inch wide flaps for proper coverage. The mounting brackets remain the same for both configurations, but ensure you select the correct width to prevent tire spray and meet DOT requirements for your specific setup.

What's the difference between rubber and stainless steel backed mud flaps?

Rubber mud flaps are more economical and flexible, making them ideal for standard highway use and easier installation. They typically last 2-3 years with regular use. Stainless steel backed flaps feature a metal plate bonded to heavy-duty rubber, offering superior durability and a professional appearance. They resist bending in high winds, maintain their shape better, and can last 5-7 years, making them worth the extra investment for long-haul applications.

Do I need to drill new holes or modify my frame for installation?

Most Peterbilt 375/377 trucks have existing mounting points that align with standard mud flap brackets, so drilling is rarely necessary. However, trucks previously equipped with custom or aftermarket flaps may require minor adjustments. The installation typically takes 30-45 minutes per side using basic hand tools. If your truck has been modified or has damage to the original mounting area, professional installation may be recommended.

How do I know if I need anti-sail brackets for my mud flaps?

Anti-sail brackets are recommended if you frequently drive in windy conditions, operate at highway speeds over 65 mph regularly, or have experienced mud flaps flipping up or wearing prematurely. They're especially important for trucks with aerodynamic side skirts or those pulling flatbed trailers where crosswinds are common. Standard brackets work fine for local delivery or lower-speed applications, but anti-sail brackets add minimal cost while significantly extending mud flap life.