Frequently Asked Questions About Mack RD Truck Mud Flaps

What size mud flaps do I need for my Mack RD, and will they fit my specific year model?

Mack RD trucks typically require 24" x 30" or 24" x 36" mud flaps, depending on your tire size and state regulations. These mud flaps are compatible with Mack RD models from 1990-2004, including RD688, RD690, and RD800 series. For dump trucks or vehicles with oversized tires, you may need the larger 24" x 36" size. Always measure from the bottom of your fender to ensure proper ground clearance - most states require 6-8 inches maximum gap between the mud flap bottom and the road surface.

What material should I choose - rubber or poly, and how thick should they be?

For Mack RD trucks, we recommend heavy-duty rubber mud flaps with a minimum thickness of 3/8" to 1/2" for durability against road debris and harsh conditions. Rubber mud flaps offer better flexibility in cold weather and resist cracking, while poly mud flaps are lighter and resist chemical damage from road salt and oil. If you operate in extreme cold climates below -20F, rubber performs better. For chemical resistance and weight savings, poly is ideal. Both materials should meet DOT requirements for commercial vehicles.

Do I need special brackets or hardware to install mud flaps on my Mack RD?

Most Mack RD trucks have existing mud flap bracket mounting points on the frame rails behind the rear wheels. You'll typically need anti-sail brackets (spring-loaded or standard) to prevent the mud flaps from blowing back while driving. The installation usually requires 1/2" or 5/8" bolts with lock washers and nuts. For trucks without existing brackets, universal mud flap hangers that clamp to the frame rail are available. Installation typically takes 30-45 minutes per side with basic hand tools.

What's the difference between anti-sail and standard mud flaps for my Mack RD?

Anti-sail mud flaps include spring-loaded brackets or weighted bottom bars that keep the mud flaps hanging straight down, even at highway speeds. Standard mud flaps can blow backward (sail) when driving, reducing their effectiveness and potentially causing damage. For Mack RD trucks that frequently travel at highway speeds or in windy conditions, anti-sail systems are highly recommended. They add about $20-40 per set but significantly improve performance and reduce wear on the mud flaps themselves.

Are logo or custom mud flaps worth the extra cost for my Mack RD?

Logo mud flaps with the Mack Bulldog or custom text typically cost 20-30% more than plain mud flaps but offer several benefits. They enhance your truck's professional appearance, which can be important for owner-operators and fleet vehicles. The logos are usually molded or embossed into the rubber, making them extremely durable - they won't peel or fade like stickers. Plain black mud flaps work perfectly fine for functionality, but many Mack RD owners find the branded options worth the investment for the improved appearance and pride of ownership.