Gates 31838D Fuel Tank Cap

Diesel Fuel Cap for Ram and Dodge Applications

The Gates 31838D Diesel Only Fuel Cap is built for diesel fuel systems that use a quick-on, pressure-vacuum style cap. Its traditional green cover identifies diesel service and matches common diesel nozzle handles for easier fuel identification at the pump.

Compatible with select Ram 2500, Ram 3500, Ram ProMaster diesel applications, plus certain Dodge Ram, Jeep, and Mercedes-Benz models, this fuel tank cap is a direct-fit service part for vehicles that require a diesel-only cap. The Gates Diesel Only Fuel Cap line focuses on correct fuel identification and OE-style fitment for diesel-equipped vehicles.

Key Features

• Diesel only fuel cap with green cover for clear fuel identification
• Quick-On cam type for straightforward cap engagement
• Pressure-vacuum venting for fuel tank system operation
• Non-lockable design
• Thread diameter: 1.78 in.
• Shell diameter: 2.78 in.
• Depth: 2.41 in.
• Gates part number 31838D

Detailed Description

Gates 31838D is a diesel fuel tank cap designed for vehicles that use a pressure-vacuum, quick-on style closure. The green cap cover provides a clear diesel-only visual cue, which is especially useful for Ram 2500 and Ram 3500 diesel trucks, as well as Ram ProMaster diesel vans and select Dodge, Jeep, and Mercedes-Benz diesel models. This part cross-references Stant 10838D for the same application.

Use Gates 31838D when you need a replacement diesel fuel cap that matches the required venting and attachment style for the fuel system. The cap is intended for diesel-only service and is not lockable.

Vehicle Fitment

• Fits 2011-2024 Ram 2500, N/A; Green; Diesel Only Fuel Cap
• Fits 2011-2024 Ram 3500, N/A; Green; Diesel Only Fuel Cap
• Fits 2014-2016 Ram 1500, N/A; Green; Diesel Only Fuel Cap
• Fits 2014-2016 Ram ProMaster 1500, N/A; Diesel Only Fuel Cap
• Fits 2014-2016 Ram ProMaster 2500, N/A; Diesel Only Fuel Cap
• Fits 2014-2016 Ram ProMaster 3500, N/A; Diesel Only Fuel Cap
• Fits 2000-2010 Dodge Ram 2500, N/A; Green; Diesel Only Fuel Cap
• Fits 2000-2010 Dodge Ram 3500, N/A; Green; Diesel Only Fuel Cap
• Fits 2007-2009 Jeep Grand Cherokee, N/A; Green; Diesel Only Fuel Cap
• Fits 2007-2009 Mercedes-Benz GL320, N/A; Green; Diesel Only Fuel Cap
• Fits 2007-2009 Mercedes-Benz ML320, N/A; Green; Diesel Only Fuel Cap
• Fits 2007-2009 Mercedes-Benz R320, N/A; Green; Diesel Only Fuel Cap
• Fits 2005-2006 Jeep Liberty, N/A; Green; Diesel Only Fuel Cap

Common Issues This Part Addresses

• Damaged or worn diesel fuel cap that no longer seals properly
• Missing diesel-only cap on a Ram, Dodge, Jeep, or Mercedes-Benz diesel application
• Incorrect fuel cap identification at the pump
• Fuel tank venting concerns related to a failed cap
• Replacement need for a quick-on, pressure-vacuum fuel cap

Installation Notes and Tips

Confirm the vehicle uses a diesel-only, quick-on fuel cap with pressure-vacuum venting before ordering. Match the cap style and dimensions to the original part, and verify the fuel tank neck design on the vehicle. For best results, inspect the sealing surface and fuel filler neck for wear or damage before installing the replacement cap.

Quality Assurance

Gates manufactures fuel system service parts with application-specific fitment and functional specifications. The 31838D is built to match the diesel-only cap style used on the listed Ram, Dodge, Jeep, and Mercedes-Benz applications.