What is the required clearance from the ground to the bottom of the mudflap?

Post date: Apr 22, 2012 1:20:36 AM

In the PA Safety Inspection regulations regarding mudflaps it references PA Vehicle Code Title 75 § 4533 which states:

"Every truck with a gross weight exceeding 11,000 pounds, trailer and truck tractor (without a semitrailer) driven on a highway shall be so constructed or equipped as to bar water or other road surface substances thrown from the rear wheels of such vehicle or combination at tangents exceeding 22 1/2 degrees, measured from the road surface, from passing in a straight line to the rear of such vehicle or combination."

This means that there is no set height per se; it depends how far the mudflap is located behind the axle. You can find a chart illustrating this and giving the dimensions here. For example, if the mudflap is 24" behind the center line of the axle it must be within 10" of the ground; while if it is is 36" behind the center line of the axle it must be within 15" of the ground. This is the maximum height for the mudflaps, they could of course be lower than this.

Note: It is important to also note that this requirement only applies to trucks with a GVWR exceeding 11,000 pounds; meaning that it does not apply to passenger cars and light trucks, however it does apply to all trailers.