Weather Guard Underbody Boxes

Shop Weather Guard underbody boxes for flatbed and service body trucks. An underbody box mounts beneath the deck, adding lockable storage without using any deck space. Weather Guard underbody boxes come in 24-, 30-, 36-, 48- and 60-inch lengths, in 18 x 18-inch and 24 x 24-inch profiles, plus a compact 24 x 14 x 11-inch steel box. Steel models come in gloss black; aluminum models come in bright aluminum and gloss black. They're American-made, backed by a limited lifetime warranty, and most orders ship within 1 business day from our strategically located warehouses across the US. Compare every style in Weather Guard tool boxes or see the full Weather Guard lineup.

Choosing an Underbody Box

Measure the open length under your deck and the clearance between the deck and the frame before you order, then match the box length and profile to that space. Check each product page for mounting details.

Related Weather Guard Equipment

Running a service body? See Weather Guard truck ladder racks, including the service body rack. To compare other brands, shop all underbody boxes.

Weather Guard Underbody Box FAQs

What is an underbody tool box?

An underbody tool box mounts beneath the deck of a flatbed or service body truck, adding lockable storage without taking up deck space.

What sizes do Weather Guard underbody boxes come in?

Lengths are 24, 30, 36, 48 and 60 inches, in 18 x 18-inch and 24 x 24-inch profiles, plus a compact 24 x 14 x 11-inch steel box.

How do I know which underbody box fits my truck?

Measure the open length under your deck and the clearance to the frame, then compare those numbers to each box's dimensions. Contact our team with your truck and body details if you need help.

Should I choose a steel or aluminum underbody box?

Aluminum saves weight. Steel underbody boxes come in gloss black; aluminum boxes come in bright aluminum and gloss black, and the two are priced differently.

Are Weather Guard underbody boxes made in the USA?

Yes. Weather Guard underbody boxes are American-made and backed by a limited lifetime warranty against defects in materials and workmanship.