3.37 Inch ID Kenworth - Locking Fuel Cap - Vented/Non-Vented - Chrome

Inner Diameter: 3.37" Cap Assy Alum 3.5”- 5.5 NS Chrome Full Function Vented 190°F, Thermal W/Pressure Relief 8.00” Chain & 6.50” Bail, W/ 'DIESEL ONLY KEEP CLEAN & VENTED CAP' May be used with vented or non-vented tank ID under cap 90-00979 Sold individually; image shows top and underside of cap HOW TO SIZE A LOCKING FUEL CAP FITMENT: We want to make sure you get the locking fuel cap cover that fits your truck! If you have any questions or concerns about fitment, please contact us by chat, our contact form or by phone. Note: Unless someone from our team recommended or advised you to buy a particular cover, you are responsible for return shipping costs. Use the following directions to determine which cap is right for your truck: All Cap designs/styles have been "Drop Tested" to meet DOT qualifications for HWY Transportation Fuel Tank safety. FMCSA-39367 Always measure the inside diameter (ID) of Fuel Cap for a more positive Identification if there is any question as to which Cap to use. Should the Cap not be available - measure the outside diameter (OD) of the Fill Tank Neck to determine inside Diameter (ID) of Cap. Always make sure and if the Tank is either Vented or non-Vented in order to spec correct Vented or Non-Vented Cap. (note: a Vented Cap is made to work with a non-Vented Tank; it is also safe to use on a Diesel Fuel Tank that is already Vented) a non-Vented Tank Must have a Vented Cap to operate properly. The inside diameter (ID) of Caps used with Low-Sulfur labeled Diesel Fuel Tanks are smaller and have different treads than Caps used with Diesel Fuel Tanks that have no Low Sulfur Label.  All Caps are Threaded Female style. (except the Peterbilt Lever Style and Freightliner Cam-Cap Style) Some Older Fuel Tank fill necks (pre 2000) may have a different size and thread than current Tanks. Though Steel Tanks are not as common in the HD Truck Industry as Aluminum, it is recommended to clarify whether the tank is Aluminum or Steel.