Gates 31703 Fuel Tank Cap

Gates 31703 Regular Locking Fuel Cap

The Gates 31703 regular locking fuel cap is built for direct replacement on a wide range of Porsche, Mazda, Volkswagen, Audi, Hummer, Saab, Cadillac, and Chevrolet applications. It features a lockable design and a non-vented construction to help maintain proper fuel system sealing while meeting OEM specifications and emission requirements.

Key Features

• Lockable regular fuel cap design for added fuel tank security
• Non-vented construction for applications that require a sealed cap
• Two-way pressure relief and vacuum relief valve helps the tank breathe while limiting fuel vapor escape
• Threaded cam type for secure engagement
• Built to meet OEM specifications and Federal and State emission requirements
• Thread diameter: 1.77 in.; shell diameter: 2.91 in.; depth: 2.61 in.

Product Details

Gates Regular Locking Fuel Cap part number 31703 is a direct-fit fuel tank cap for vehicles that require a threaded, non-vented locking cap. The design supports proper tank pressure management through a two-way relief valve, helping control vacuum and pressure changes during normal operation. This makes it a practical replacement for aging or damaged caps on Porsche 911, Porsche Boxster, Porsche Cayman, and other listed applications. This part cross-references Monroe Shocks & Struts 5796 for the same application.

What It Helps Solve

• Loose, cracked, or missing fuel cap sealing issues
• Fuel vapor leakage caused by a worn cap seal
• Check engine light concerns related to evaporative emissions faults
• Difficulty maintaining proper fuel tank pressure or vacuum balance
• Fuel theft deterrence on lockable-cap applications

Installation Notes and Tips

Verify the cap style, thread diameter, and venting requirements before installation. This Gates 31703 fuel cap uses a threaded, non-vented design, so it should be matched only to vehicles listed with the same cap type. Confirm the cap seats fully and locks securely after installation. For fitment reference, it fits 1974-2010 Porsche 911, 1997-2012 Porsche Boxster, 2006-2012 Porsche Cayman, and 2004-2010 Volkswagen Touareg. It also fits 2007 Audi Q7 and 2006 Porsche Cayenne.

Quality Assurance

Gates manufactures this fuel tank cap to OEM specifications and to meet Federal and State emission requirements. The locking design and pressure relief/vacuum relief valve reflect the brand’s focus on proper sealing and fuel system function for applications such as Porsche 911, Porsche 944, and Mazda 626. Part number 31703 is engineered for consistent replacement performance across the listed fitments.