Gates 31840 Fuel Tank Cap

Regular Locking Fuel Cap for Toyota and Lexus

The Gates 31840 Regular Locking Fuel Cap is a direct replacement fuel tank cap for select Toyota, Lexus, Scion, and Pontiac applications. It is built to meet OEM specifications and emission requirements while helping seal the fuel system and control vapor loss.

Gates’ Regular Locking Fuel Cap line focuses on OE-style fit and function for everyday service replacement. This cap uses a quick-on cam design with emission control venting and a two-way pressure relief/vacuum relief valve to let the tank breathe while limiting fuel vapor escape.

• Lockable fuel cap for added fuel system security
• Quick-On cam type for straightforward installation on listed applications
• Emission control venting to support evaporative emissions performance
• Two-way pressure relief and vacuum relief valve
• Regular fuel cap design for select threaded filler neck applications
• Thread diameter: 1.56 in.; shell diameter: 2.68 in.; depth: 2.6 in.

Detailed Product Overview

Use the Gates 31840 fuel tank cap when you need a replacement that matches the original-style locking cap used on many Toyota and Lexus vehicles. This part number 31840 is listed for applications such as the 2003-2006 Toyota Camry, 2004-2006 Toyota Highlander, 2003-2009 Toyota 4Runner, 2004-2009 Toyota Prius, 2005-2008 Toyota Tacoma, 2003-2009 Lexus GX470, and 2013-2014 Lexus GS350. It is also listed for select Scion tC, Pontiac Vibe, and Toyota Matrix models.

This part cross-references Quality-Built 11509 for the same application.

What It Helps Address

• Loose, damaged, or missing fuel cap
• Fuel vapor leakage from a worn seal or locking mechanism
• Check engine light concerns related to evaporative emissions faults
• Difficulty maintaining proper fuel tank pressure or vacuum balance
• Need for a direct replacement locking cap on listed Toyota and Lexus models

Installation Notes and Tips

Verify the filler neck style before ordering. This cap is listed for vehicles with a regular locking fuel cap design, and some applications note use without a threaded filler neck. Confirm the thread diameter and shell dimensions against the original cap before installation. After installation, tighten until the cap seats fully and locks as intended.

Quality Assurance

Gates states that this locking fuel tank cap meets OEM specifications and Federal and State emission requirements. The integrated pressure relief and vacuum relief valve is designed to support proper tank breathing while helping control fuel fumes.