Dynamax Force HD Locking Fuel Door — Security Your Super C Deserves
The Dynamax Force HD is one of the most capable Super C motorhomes on the road — built on the Ford F-550 with the 6.7L Power Stroke. But Dynamax left the diesel and DEF caps completely exposed. The RV Fuel Vault is the exact-fit armored locking enclosure that finally seals them.
The Problem
- ✖Your Dynamax Force HD left the factory with completely exposed diesel and DEF caps — no fuel door
- ✖The F-550 Power Stroke carries 50-80 gallons of diesel — a theft magnet at campgrounds and truck stops
- ✖DEF contamination from tampering can destroy your emissions system — a $5,000-$10,000 repair
- ✖Cheap locking caps can be pried off in seconds and leave your DEF tank completely unprotected
- ✖Road debris and diesel splash-back damage the paint around your exposed filler area
The RV Fuel Vault Solution
- Factory-finished look — eliminates exposed diesel and DEF caps on your Force HD
- Precision-engineered for the Dynamax Force HD on Ford F-550 filler neck configuration
- Tamper-resistant keyed lock secures both diesel fuel and DEF fluid simultaneously
- High-strength fiber-filled polymer — built for full-time Super C ownership
- Bolt-on in 8-15 minutes — no drilling, no cutting, no modifications
- Corrosion-proof construction rated for year-round use in any climate
See the Difference
Why You Need a Locking Fuel Door
Lead with finish. End with security.
Factory-Finished Look
Eliminates the exposed plastic caps on your Force HD. Your rig finally looks factory-complete.
Fuel Theft Prevention
Keyed lock stops siphoning at campgrounds, rest stops, and storage facilities.
DEF Contamination Defense
Prevents tampering with your DEF tank — avoids $5K-$10K SCR system repairs.
Vandalism Protection
Tamper-resistant design deters opportunistic damage to your fuel system.
Installs in 8–15 Minutes — No Drilling, No Cutting
8–15 Minutes
Average install time
Basic Hand Tools
No special equipment needed
100% Reversible
No drilling, no cutting, no mods
Compatible Ford F-550 (Dynamax Force HD) Motorhomes
The Dynamax Force HD is built on the Ford F-550 with the 6.7L Power Stroke diesel. Like all F-550 Super C motorhomes, both diesel and DEF filler necks are completely exposed from the factory.
| Manufacturer | Models / Floorplans |
|---|---|
| Dynamax Force HD | All floorplans (34KD, 36FK, 37BH, etc.) on Ford F-550 |
| Dynamax DX3 | All floorplans on Ford F-550 |
| Also fits other F-550 Super C | Entegra Accolade XT, Jayco Seneca |
Frequently Asked Questions
Common questions about The RV Fuel Vault on Ford F-550 (Dynamax Force HD) motorhomes
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Order My RV Fuel VaultProudly Made in the USA · Patent Pending 64/085,223 · Est. delivery by July 4, 2026