20 Gallon Fuel Cell for LWB Conversion / 15" Stretch - Jeep YJ / TJ / LJ

Whether you already have a Jeep LJ running a Motobilt LJ Back Half Kit, are converting a standard-wheelbase TJ to LJ dimensions, or are stretching a YJ to LJ length with the Motobilt 15" Stretch Back Half, fuel tank placement becomes an important part of the rear chassis layout. The MB5074 was designed specifically for these builds, allowing the fuel cell to mount between the rear frame rails behind the axle instead of taking up valuable cargo space inside the Jeep. In the past, one of the common solutions was putting a fuel cell inside the Jeep behind the seats. That takes up valuable cargo room and puts the fuel cell inside the passenger compartment. The Motobilt MB5074 20 Gallon Fuel Cell was designed to move that fuel storage out of the interior and into the space created by the new rear chassis layout. The MB5074 mounts between the rear frame rails and behind the rear axle, keeping the cargo area open while providing 20 gallons of fuel capacity. It is designed around the Motobilt MB3067 15" Stretch Back Half for the Jeep YJ, the MB3020-S and MB3020-W LJ Back Half Kits commonly used to convert a Jeep TJ to LJ dimensions, and the upcoming MB3082 LWB Conversion Back Half. The 20-gallon fuel cell is constructed from 5052 aluminum and protected underneath by an A36 steel skid plate. A CNC-machined aluminum filler neck with a threaded cap and O-ring provides a secure fill point. A brass rollover valve and vent hose are included for tank venting, along with a 1/2" plugged port that can be used as a return port when required by the fuel system. The MB5515 fuel pump mounting ring is already welded into the tank. This provides the mounting interface for a compatible fuel pump, but the fuel pump itself is not included. The MB5515 setup also includes a blank plate, giving builders a starting point for custom fittings or an aftermarket fuel pump configuration. This is not a universal YJ or TJ fuel cell. It is a purpose-built fuel system for stretched YJs, TJ-to-LJ conversions, factory LJ builds using the compatible back halves, and other specifically listed Motobilt LWB back half applications. Important Information 20-gallon fuel capacity Mounts between the rear frame rails and behind the rear axle Keeps the fuel cell out of the passenger and cargo area Designed for YJ 15-inch stretch and TJ-to-LJ length conversion applications Compatible with MB3067 15" Stretch Back Half for Jeep YJ Compatible with MB3020-S LJ Back Half with Stubby Bumper Compatible with MB3020-W LJ Back Half MB3020-S and MB3020-W can be used when converting a standard-wheelbase TJ to LJ dimensions Compatible with upcoming MB3082 LWB Conversion Back Half Does not fit standard YJ or TJ back half kits Fuel cell constructed from 5052 aluminum Skid plate constructed from A36 steel MB5515 fuel pump mounting ring is installed and welded into the fuel cell Fuel pump is not included Includes MB5515 blank plate for custom fuel system applications Includes CNC-machined aluminum filler neck Threaded filler cap uses an O-ring seal Includes brass rollover valve and vent hose Includes 1/2" plugged port that can be utilized as a return port Includes necessary mounting brackets and rubber strips Optional MB5031 Universal Fuel Access Hatch Kit sold separately Made in the USA Product Specifications Vehicle / Application Fitment Jeep YJ with MB3067 15" Stretch Back Half Jeep TJ converted to LJ dimensions using MB3020-S or MB3020-W Jeep LJ with MB3020-S or MB3020-W Back Half LWB conversion using upcoming MB3082 Back Half Part Number MB5074 Fuel Capacity 20 Gallons Fuel Cell Material 5052 Aluminum Skid Plate Material A36 Steel Dimensions 12.5" H x 37" W x 9.5" D Weight 116 lbs total for fuel cell and skid plate Fuel Pump Mount MB5515 fuel pump mounting ring installed and welded to fuel cell Fuel Pump Not included Filler CNC-machined aluminum filler neck with threaded cap and O-ring seal Venting Brass rollover valve and vent hose included Additional Port 1/2" plugged port that can be used as a return port depending on fuel system configuration Mounting Mounting brackets and rubber strips included Manufactured Made in the USA Installation Notes The MB5074 mounts between the rear frame rails and behind the rear axle. This location is made possible by the chassis layout created by the compatible Motobilt stretch and back half systems. When installing the MB5074 with the MB3067, MB3020-S, or MB3020-W, the installer will need to drill the required mounting holes into the back half and weld nuts in place for mounting. The necessary fuel cell mounting brackets and rubber strips are included. The fuel pump is not included. The MB5515 fuel pump mounting ring is already welded into the tank and provides the mounting interface for the fuel pump. The included MB5515 blank plate can be modified by the builder for custom fittings or an aftermarket fuel pump configuration. For builders who want access to the fuel pump from above, the Motobilt MB5031 Universal Fuel Access Hatch Kit is available separately. Fuel system plumbing, venting, electrical connections, and final configuration must be completed for the specific vehicle and fuel system being used. Frequently Asked Questions Can I use the MB5074 when converting my Jeep TJ to LJ dimensions? Yes. This is an important application for the MB5074. When a standard-wheelbase Jeep TJ is converted to LJ dimensions using the Motobilt MB3020-S or MB3020-W LJ Back Half Kit, the MB5074 provides a 20-gallon fuel cell designed to package between the new rear frame rails and behind the axle. Do I need to start with a factory Jeep LJ to use this fuel cell? No. The MB3020-S and MB3020-W LJ back half systems can be used as part of a TJ-to-LJ length conversion. The MB5074 works with these back half configurations whether the build starts as a standard-wheelbase TJ or uses the compatible LJ configuration. What problem does the MB5074 solve on a stretched YJ or TJ-to-LJ conversion? Once the rear chassis is stretched or converted to LJ dimensions, the fuel system needs to work with the new frame and suspension layout. Instead of putting a fuel cell behind the seats and sacrificing cargo room, the MB5074 positions 20 gallons of fuel between the rear frame rails and behind the axle. What Motobilt back half kits does the MB5074 fit? The MB5074 fits the MB3067 YJ 15" Stretch Back Half, MB3020-S LJ Back Half with Stubby Bumper, MB3020-W LJ Back Half, and the upcoming MB3082 LWB Conversion Back Half. Will the MB5074 fit a standard YJ or TJ back half? No. This fuel cell is specifically packaged around the listed stretch and LWB back half configurations. It does not fit standard YJ or TJ back half kits. Where does the fuel cell mount? The MB5074 mounts between the rear frame rails and behind the rear axle. This keeps the fuel cell outside the passenger compartment and preserves usable cargo space behind the seats. Does the MB5074 include a fuel pump? No. The fuel pump is not included. The MB5515 fuel pump mounting ring is already welded into the aluminum fuel cell. Can I use a custom or aftermarket fuel pump setup? The included MB5515 setup comes with a blank plate that gives fabricators a starting point for custom fuel system configurations. Builders can modify the plate for fittings or use it when adapting an aftermarket fuel pump. Does the fuel cell include a filler neck and vent? Yes. The MB5074 includes a CNC-machined aluminum filler neck with a threaded cap and O-ring seal. A brass rollover valve and vent hose are also included. Can I run a fuel return line? The fuel cell includes a 1/2" plugged port that can be utilized as a return port if required by the fuel system. Is a fuel pump access hatch included? No. An access hatch is not included. The Motobilt MB5031 Universal Fuel Access Hatch Kit is available separately for builders who want to incorporate service access from above. Does the MB5074 include a skid plate? Yes. The system includes the 5052 aluminum 20-gallon fuel cell and an A36 steel skid plate to protect the tank in its rear chassis mounting location.