Gates 31775 Fuel Tank Cap

Gates 31775 Regular Locking Fuel Cap

The Gates 31775 regular locking fuel cap is built for older Dodge, Chevrolet, GMC, Buick, Pontiac, Chrysler, and Oldsmobile applications that require an emission-controlled, lockable fuel tank cap. It is engineered to meet OEM specifications and support Federal and State emission requirements while helping the fuel system maintain proper pressure and vacuum balance.

Key Features

• Lockable regular fuel cap for added fuel tank security
• Two-way pressure relief and vacuum relief valve helps the tank breathe
• Emission control venting for regulated fuel systems
• Deep cam design for proper cap engagement
• 1.38 in. thread diameter, 3.25 in. shell diameter, 2.09 in. depth
• Gates 31775 fuel cap for OE-style replacement needs

Product Details

This Gates locking fuel tank cap is designed for vehicles that use a regular fuel cap with emission control venting. The pressure relief and vacuum relief function helps manage tank breathing while limiting fuel vapor escape, which is important on classic trucks and cars such as Dodge D100, D150, Ramcharger, Chevrolet C10, K5 Blazer, and GMC Jimmy applications. If you need a direct replacement fuel cap for a vintage truck or passenger car, Gates 31775 provides the fitment and sealing style expected for these systems. This part cross-references Dorman - Conduct-Tite 84772 for the same application.

What It Helps Address

• Loose or missing locking fuel cap
• Fuel vapor loss from a worn cap seal
• Emission-control issues caused by a non-venting or incorrect cap
• Improper tank pressure or vacuum balance
• Replacement needs for aging OE fuel tank caps

Installation Notes and Tips

Verify the cap style, thread diameter, and cam design before installation. This Gates 31775 fuel cap is listed for regular locking fuel cap applications and should be matched to the vehicle’s filler neck and emission-control setup. Confirm fitment for the exact year, make, and model, especially on Dodge trucks with cab tank or threaded filler neck variations. Fits 1975-1980 Dodge D100, W/O Cab Tank; W/O Threaded Filler Neck; Fits 1975-1978 Chevrolet C10, N/A; Fits 1973-1978 GMC Jimmy, N/A.

Quality Assurance

Gates states that this locking fuel tank cap meets OEM specifications and Federal and State emission requirements. The design uses a two-way pressure relief and vacuum relief valve to support proper fuel system operation on emission-controlled applications.