Does The RV Fuel Vault fit the Grand Design Lineage?

Yes. It is engineered specifically for the Ram 5500 chassis filler configuration used in the Lineage.

Will it fit every Lineage floorplan?

Yes. All Lineage floorplans share the same Ram 5500 chassis and filler configuration.

Does it also fit the Dynamax Isata 5?

Yes. The Isata 5 is also built on the Ram 5500 chassis with the same filler configuration.

How long does installation take?

8-15 minutes with basic hand tools. No drilling, no cutting.

Limited Lifetime Warranty plus a 30-day satisfaction guarantee.

Built for the Lineage

Grand Design Lineage Locking Fuel Door — Secure Your Ram 5500 Super C

The Grand Design Lineage is Grand Design's first Super C — built on the Ram 5500 chassis with the Cummins 6.7L diesel. Grand Design left the fuel caps completely exposed. The RV Fuel Vault is the exact-fit armored locking enclosure your Lineage needs.

The RV Fuel Vault — Grand Design Lineage — locking fuel door for motorhomes

The Problem

✖Your Grand Design Lineage has exposed, unlocked fuel caps — no factory fuel door
✖The Cummins 6.7L carries a large diesel fuel supply — a theft target at every stop
✖Fuel contamination from tampering can cause catastrophic engine damage and costly repairs
✖Generic locking caps are easily defeated and only protect one filler at a time
✖Road debris and fuel splash-back damage the finish around your exposed filler area

The RV Fuel Vault Solution

Factory-finished look — eliminates exposed fuel caps on your Lineage
Precision-engineered for the Grand Design Lineage on Ram 5500 filler configuration
Tamper-resistant keyed lock secures your fuel system
High-strength fiber-filled polymer — built for premium 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

✖ Exposed caps on Lineage — no security

✓ RV Fuel Vault installed — sealed and locked

Why You Need a Locking Fuel Door

Lead with finish. End with security.

Factory-Finished Look

Eliminates the exposed plastic caps on your Lineage. Looks factory-installed.

Fuel Theft Prevention

Keyed lock stops siphoning at campgrounds, rest stops, and storage facilities.

Contamination Defense

Prevents sugar, water, or foreign substances from being added to your fuel tank.

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 Ram 5500 (Grand Design Lineage) Motorhomes

The Grand Design Lineage is built on the Ram 5500 with the Cummins 6.7L diesel. The fuel caps are completely exposed from the factory.

Manufacturer	Models / Floorplans
Grand Design Lineage	All floorplans on Ram 5500
Dynamax Isata 5	All floorplans on Ram 5500

Don't see your model? Use the Fitment Finder — we likely fit your rig.

Frequently Asked Questions

Common questions about The RV Fuel Vault on Ram 5500 (Grand Design Lineage) motorhomes

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Order Today — Starting at $99.95

Single Door, Set of 2, or 3-Pack · Free Shipping · Limited Lifetime Warranty · 30-Day Guarantee

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Proudly Made in the USA · Patent Pending 64/085,223 · Est. delivery by July 4, 2026