Gates 31778DKA Fuel Tank Cap

Diesel Fuel Cap Security for Fleet Use

The Gates 31778DKA Diesel Only Keyed Alike Fuel Cap is built for diesel fuel tank security with the convenience of a single-key setup across multiple vehicles. It is a lockable, Quick-On style fuel tank cap with pressure-vacuum venting for applications that require controlled tank breathing.

Compatible With 2004 Chevrolet Silverado 2500 HD and 2004 Chevrolet Silverado 3500 diesel applications, plus select Toyota Pickup, Toyota Camry, Toyota Corolla, Volvo 740, Volvo 745, and Volvo 760 diesel models. The keyed-alike design is well suited for fleets and like-model vehicles where one key system simplifies daily fueling access.

• Brand: Gates
• Part Number: 31778DKA
• Diesel Only fuel tank cap
• Lockable design for added fuel security
• Keyed alike configuration for shared-key fleet use
• Quick-On cam type for straightforward cap engagement
• Pressure-vacuum venting
• Black and green finish
• Shell diameter: 2.91 in.
• Thread diameter: 1.77 in.
• Depth: 2.61 in.

Product Details and Fitment

The Gates Diesel Only Keyed Alike Fuel Cap is intended for diesel fuel systems that use a lockable, vented cap with Quick-On cam engagement. The keyed-alike format reduces key management across fleets and multiple like-model vehicles, while the pressure-vacuum venting helps maintain proper tank operation during normal fuel use. Part number 31778DKA also cross-references 17591D for the same application.

Fits 2004 Chevrolet Silverado 2500 HD, N/A. Fits 2004 Chevrolet Silverado 3500, N/A. Fits 1984-1987 Toyota Pickup, N/A. Fits 1984-1986 Toyota Camry, N/A. Fits 1984-1985 Toyota Corolla, N/A. Fits 1985-1986 Volvo 740, N/A. Fits 1985 Volvo 745, N/A. Fits 1983-1985 Volvo 760, N/A.

What This Fuel Cap Helps Address

• Loose or missing diesel fuel cap security
• Fuel tank access control for fleet vehicles
• Cap replacement needs on keyed diesel applications
• Venting issues related to a worn pressure-vacuum cap
• Key management problems across multiple like-model vehicles

Installation Notes and Tips

Verify the fuel filler neck style, cam engagement, and diesel-only application before installation. Confirm the shell diameter, thread diameter, and depth match the original cap specification for your vehicle. For best results, compare the existing cap to the Gates 31778DKA before use on a 2004 Chevrolet Silverado 2500 HD, 2004 Chevrolet Silverado 3500, or the listed Toyota and Volvo diesel models.

Quality Assurance

Gates is a recognized name in automotive fuel system hardware, and this fuel cap follows the brand’s focus on application-specific fit and functional replacement parts. The keyed-alike design and vented construction support consistent use in diesel fleet and passenger applications.