Locking Fuel Door for Class A Gas Motorhomes (Ford F53 & Workhorse)

Estimated read time: 7 minutes

Most conversations about RV fuel security focus on diesel Super C rigs — but the single most common gas motorhome platform on the road, the Ford F53 (and the older Workhorse W-series), has exactly the same problem. Your Class A gasser rolled off the line with a large-diameter fuel filler and, in most cases, no real fuel door at all — just an exposed, unlocked cap tucked into the sidewall.

If you own a Class A gas coach built on the F53 chassis — Thor, Fleetwood, Forest River, Coachmen, Jayco, Tiffin Open Road, and dozens more — this guide explains why the fuel area is vulnerable and how a purpose-built locking fuel door fixes it.

Why the F53 fuel cap is an easy target

The F53 is a front-engine gas chassis with a big 55–80 gallon tank. On a Saturday at full pump prices, that is a lot of gasoline sitting behind a cap that anyone can twist off in the dark. Three things make it a target:

• It is exposed. Unlike your family car, there is no spring-loaded body door hiding and protecting the cap.
• It is unlocked. The factory cap is a simple twist-on — no key, no deterrent.
• It is predictable. Thieves know exactly where the fill is on a F53 coach, because they are all laid out the same way.

Gas is arguably an easier target than diesel: it is easier to resell informally, and gasoline coaches rarely have the anti-siphon hardware that newer diesel trucks carry.

Theft is only half the risk

The catastrophic risk isn't fuel loss — it's contamination. Sugar, water, sand, or a soda poured down an open gas filler can wreck a fuel system. On a modern port-injected gas V10 or the 7.3L Godzilla V8, replacing contaminated tanks, pumps, and injectors runs into the thousands, and insurers often push back on "vandalism" claims when the fill was left wide open. A locked door removes the opportunity entirely.

What to look for in a locking fuel door for a Class A gasser

1. Bolt-on fitment — it should mount over the existing filler cutout with no cutting or drilling.
2. A real, keyed lock — tamper-resistant, not a decorative latch.
3. Heavy-duty material — UV-stable, so it won't fade and crack like thin OEM plastic in the desert sun.
4. Clean, finished look — it should look like the coach came that way.

The RV Fuel Vault checks every box. It is a 3/16" fiber-filled polymer door with a tamper-resistant keyed lock that bolts on in about 8–15 minutes using basic hand tools. It is made in the USA and backed by a Limited Lifetime Warranty.

Fitment

The RV Fuel Vault is designed for the exposed-cap configuration found on Class A gas coaches (F53 and Workhorse), as well as Class C, Super C, and Class B chassis. Use the fitment finder to confirm your year, make, and model before ordering.

Bottom line

If you own a Class A gas motorhome, your fuel cap is one of the least protected parts of a very expensive rig. A locking fuel door is a low-cost, one-time upgrade that stops theft, blocks contamination, and finishes the look. See fitment and order here.