Peterbilt 330/335/337 Frame Crossmembers & Covers

Frequently Asked Questions About Peterbilt 330/335/337 Frame Crossmembers & Covers

What year models of Peterbilt 330, 335, and 337 trucks are these crossmembers compatible with?

Our frame crossmembers and covers are designed to fit Peterbilt 330, 335, and 337 models from 2005 to present. However, there were minor frame dimension changes in 2008 and 2014 model years. Always verify your specific truck's frame rail spacing (typically 34" or 34.5") and crossmember mounting hole patterns before ordering. We recommend checking your OEM with our customer service team if you have a truck from these transition years.

Are these crossmembers made from steel or aluminum, and how thick is the material?

Most of our crossmembers are constructed from heavy-duty steel with thickness ranging from 3/16" to 1/4" depending on the application. Steel crossmembers come with a black powder coat finish for corrosion resistance. We also carry select aluminum options that are typically 1/4" thick and offer weight savings of approximately 40-50% compared to steel. All materials meet or exceed OEM specifications for strength and durability.

Do I need to drill new holes or make modifications to install these crossmembers?

The majority of our crossmembers are designed as direct bolt-on replacements using existing frame holes. No drilling is required for standard installations. However, if you're adding a crossmember where one didn't exist previously, or if your frame has been modified, drilling may be necessary. All crossmembers include detailed installation instructions and hole pattern templates. We recommend having installation done by a qualified technician if drilling is required.

What's the difference between a crossmember and a crossmember cover, and do I need both?

A crossmember is the structural steel or aluminum beam that connects the frame rails and provides chassis rigidity. A crossmember cover is a decorative piece that mounts over the existing crossmember for aesthetic purposes. You don't need both unless you want the added visual appeal. Covers are popular for show trucks or when the original crossmember is functional but has surface rust or wear. Covers typically add about 1/2" of thickness to the existing crossmember.

Will adding aftermarket crossmembers affect my truck's warranty or DOT compliance?

Our crossmembers are manufactured to meet or exceed OEM specifications and DOT requirements for commercial vehicles. They will not affect DOT compliance when properly installed. Regarding warranty, modifications to the frame can potentially impact manufacturer warranties on newer trucks. We recommend checking with your dealer if your truck is still under warranty. For trucks out of warranty, our crossmembers actually strengthen the frame and can help prevent stress cracks common in high-mileage medium-duty trucks.