Yes. The RV Fuel Vault fits the Grand Design Lineage, a Super C motorhome built on the Ford F-600 chassis — it is the only purpose-built locking fuel door engineered for that commercial filler-neck configuration.
Which Grand Design Lineage models does it fit?
The RV Fuel Vault is engineered for the commercial Ford (and Ram) chassis that Grand Design Lineage motorhomes are built on. Here is how the lineup breaks down:
| Chassis | Grand Design Lineage models |
|---|---|
| Super C (Ford F-600 diesel) | Lineage Series F, Lineage Limited Edition 43 Package |
Not sure which one you have? The fitment finder confirms your exact year, make, model, and floorplan in seconds.
Why Grand Design Lineage owners need it
The Lineage is a serious investment on a heavy-duty commercial chassis — and that chassis ships with the diesel and DEF caps fully exposed. Diesel siphoning and DEF contamination are real risks for a coach this size. The RV Fuel Vault locks both fill points behind a keyed, virtually unbreakable door.
- Stops fuel theft & siphoning — a keyed, virtually unbreakable door over the cap.
- Prevents contamination — no more open access to add water, sugar, or the wrong fluid.
- Built tough — 3/16″ fiber-filled polymer that is non-corrosive and resists prying.
- Factory-finished look — covers the ugly exposed cap for a clean, finished appearance.
Installation & pricing
The RV Fuel Vault is a bolt-on upgrade that most owners install in 8–15 minutes with basic hand tools — no drilling, no cutting, and no permanent modifications. Pricing starts at $109.95 (Founders Edition) for a single door, $219.90 for a set of two, and $329.85 for the 3-Pack that includes a DEF cover. Every order ships free in the Continental U.S. and is backed by a Limited Lifetime Warranty and a 30-day satisfaction guarantee.
Frequently asked questions
Does the RV Fuel Vault fit a Grand Design Lineage?
Yes. The Grand Design Lineage is built on the Ford F-600 Super C chassis, and the RV Fuel Vault is purpose-built for it. The 3-Pack covers both the diesel and DEF caps.
Does it cover the DEF cap on the Lineage?
Yes. The 3-Pack option includes a dedicated DEF cover alongside the diesel fuel covers, protecting both exposed fill points on the Lineage.
How much does it cost and how long is the install?
Pricing starts at $109.95 (Founders Edition) per door, with the DEF 3-Pack at $329.85. Installation takes 8 to 15 minutes with basic hand tools and no modifications.
Lock down your Grand Design Lineage fuel cap
Confirm your motorhome fits and protect your fuel cap with the only purpose-built locking fuel door for RVs.
Check fitment & order →
See the Grand Design Lineage fitment page
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