Installation Guide

Confirm the size before you start

Hold the door up to the fuel fill area and check that it fully covers the opening with room for the mounting flange. Small covers standard openings on E-450, F-550, F-600, and Ram 5500. Large covers oversized openings.

If it does not line up, stop and send us a photo before drilling anything.

Clean the mounting surface

Wash and dry the area around the fuel cap housing. Road film and wax keep the door from sitting flat and make mounting holes harder to mark accurately.

Inspect the fuel cap housing bezel

If the factory bezel is cracked, faded, or missing, replace it now while the area is open. A factory replacement bezel in Small or Large is available as an add-on.

Position and mark

Set the door in place, confirm it opens and closes freely without contacting body panels, compartment doors, or the fuel nozzle path, then mark the mounting holes.

Check clearance with the compartment door open — apparatus bodies are tight around the fuel fill.

Mount with the included security screws

Install the tamper-resistant screws using the included Safety Torx driver bit. Each door takes 12 screws. Snug them in a cross pattern so the door seats evenly rather than tightening one side fully first.

Do not overtighten. The extra screw in every pack is there because stripping one happens.

Test the lock and hand off the keys

Lock and unlock the door several times, confirm the fuel cap is still easy to reach with the door open, then distribute keys to every crew member and shop tech who fuels the unit. Doors ordered together are keyed alike.