Western Star 5900 SBA Deck Plate-Air Box

Frequently Asked Questions About Western Star 5900 SBA Deck Plate-Air Box

What is a deck plate-air box and what does it do on my Western Star 5900 SBA?

The deck plate-air box is the component mounted behind the cab on the frame that houses air line and electrical line connections between the tractor and trailer. It provides a mounting surface for the gladhands and electrical sockets while protecting the lines from road debris, weather, and physical damage during coupling and daily operation.

Will this deck plate-air box fit my specific Western Star 5900 SBA model year?

Deck plates and air boxes can vary by frame width, mounting hole spacing, and the configuration of gladhand and electrical socket ports depending on the model year and how your truck was originally spec'd. Before ordering, check the listed specifications against your existing unit, including overall dimensions and port count, and compare mounting hole patterns. If you're unsure, contact us with your VIN or the part number from your current deck plate so we can confirm compatibility.

What material and finish options are available, and how well do they hold up?

These deck plates and air boxes are typically available in painted steel or polished aluminum/stainless finishes. Painted steel offers a factory-matched look at a lower cost, while polished stainless or aluminum options resist corrosion better and are popular for owner-operators who want a cleaner, chromed-out appearance. Keep in mind that polished finishes require periodic cleaning and polishing to maintain their shine, especially in winter climates where road salt is present.

What's involved in installing a replacement deck plate-air box?

Installation generally involves disconnecting the existing air lines and electrical connections, unbolting the old deck plate from the frame, and mounting the replacement in its place before reconnecting the lines. Most units bolt on using existing frame holes, but you should verify that gladhand and socket placement matches your current setup so hose and cable lengths aren't affected. Basic hand tools are usually sufficient, though we recommend having a second set of hands to support the unit during removal and installation.

Are there DOT or safety requirements related to this part?

While the deck plate-air box itself isn't a specifically regulated DOT component, it houses the air and electrical connections that are subject to DOT inspection standards, including secure mounting, no damage to lines, and properly functioning gladhands and sockets. Make sure any replacement part allows for secure, undamaged routing of these lines and doesn't introduce leaks, pinch points, or loose connections that could fail inspection or cause issues on the road.