Semi-Truck Fuel Tank Caps Universal

Replace a Missing or Stuck Fuel Cap: Locking & Heavy Duty Tank Caps

We stock a wide selection of diesel fuel tank caps designed for heavy duty applications—whether you need a locking cap for extra protection, a vented cap to maintain proper tank pressure, or a standard replacement that blends with your truck’s polished look. Get the right fit. Match the cap size/thread to your filler neck (measure the diameter). Choose between locking or non-locking, and vented or non-vented caps. Lost your existing gas cap? Don’t repeat the same mistake. Grab a tether chain fuel cap accessory. Already have a non-locking fuel cap? You can add a locking fuel cap cover to push and twist on top of your existing cap. Leaking diesel from the fill point? Swap out the synthetic O-ring for an airtight seal around your cap that keeps contaminants out of your semi truck fuel tank. Here’s what you’ll find when you shop through this collection of universal-fit replacement fuel tank caps: - Locking fuel caps to keep your tank secure on the road. - Vented and non-vented fuel tank caps for maintaining system pressure. - Lever lock flush cap assemblies for a clean, aerodynamic finish. - Durable, built-to-last finishes that match your truck’s exterior. Every product is built for real-world conditions—so when you add one to your cart, you’re investing in security, reliability, and a better drive. Use the filter sort options on this page to narrow down by style, material, or fit, and get the right fuel tank cap for your rig.