NORTHWEST CONVERSIONS TRANSIT 20-GALLON UNDERCARRIAGE WATER TANK (DRIVER SIDE) - 2015+

NORTHWEST CONVERSIONS TRANSIT 20-GALLON UNDERCARRIAGE WATER TANK (DRIVER SIDE) - 2015+

At WEST COAST VANS, we know that managing your freshwater supply or greywater storage without sacrificing precious interior floor space is one of the ultimate packaging puzzles of a custom build. Sacrificing your internal layout to drop in bulky water rectangles leaves you with less room for bedding, cabinetry, and living space. Worse yet, generic aftermarket tanks rarely fit the incredibly complex, ribbed subframe geometry beneath a modern rig—leaving you to sketch up sketchy DIY strap networks that sag over rough washboard roads or hang dangerously low to the trail. We believe your plumbing infrastructure should hide completely out of sight, utilize wasted chassis space, and feature rock-solid mechanical mounting. Enter the Northwest Conversions Transit 20-Gallon Undercarriage Water Tank—explicitly engineered to mount seamlessly beneath the driver-side chassis layout right next to the factory fuel tank. This heavy-duty, high-capacity tank maximizes your off-grid endurance while keeping your interior entirely wide open. Ask Us Product Questions Anytime if you want to coordinate your sub-chassis plumbing paths or check frame bracket alignment clearances!

WCV EXPERT TIP Achieving a completely secure, trail-proof undercarriage installation requires sharing factory attachment points and utilizing proper sheet metal preparation tools before you crawl underneath. Pro Tip: Northwest Conversions brilliantly engineered this kit to use a hybrid mounting configuration to save you installation stress. One side of the three included laser-cut stainless steel support straps attaches directly to your Transit's existing fuel tank strap locations, utilizing the same factory hardware. For the opposite side of the straps near the unibody pinch weld, you will need to drill three precision 17/32" holes to set the included heavy-duty 3/8-inch Rivnuts. Make sure to use a dedicated 17/32" drill bit (not standard in most budget index boxes) and a high-leverage heavy-duty Rivnut setting tool to properly lock the threaded sleeves home. Apply an anti-corrosion primer to the raw metal edges before clamping the stainless straps down tightly—this ensures a rock-solid, zero-sway configuration that easily handles the massive 160-pound sloshing payload of a topped-off water supply on brutal backcountry trails!

PRODUCT OVERVIEW The Northwest Conversions 20-Gallon Undercarriage Water Tank is a premium, commercial-grade water management module built for modern van lifers, remote overlanders, and custom build shops. Molded in the USA from high-density, BPA-free food-grade polyethylene plastic, this highly versatile tank is fully certified to IAPMO TS-4 plumbing standards, making it completely safe to operate as a high-capacity auxiliary freshwater supply or a low-profile greywater containment center. Arriving as a comprehensive vehicle-specific upfit package featuring three precision laser-cut stainless steel brackets and high-tensile hardware, this tank is meticulously contoured to tuck entirely flush above the factory frame lines, preserving your valuable ground clearance.

BEST FOR

• HIGH-CAPACITY OFF-GRID ENDURANCE: Perfect for digital nomads and boondockers looking to double their off-grid footprint with an extra 20 gallons of hidden freshwater storage or a dedicated greywater drop tank.

• MID & LONG-WHEELBASE BUILDERS: Tailored explicitly to tuck into the mid-ship driver-side chassis bay of standard 148" and 148" Extended wheelbase Transit cargo setups.

• SPACE-OPTIMIZING DIY BUILDERS: Ideal for travelers who want to maximize interior cabinet and garage storage by relocating bulky plumbing infrastructure completely underneath the vehicle frame.

TECHNICAL SPECIFICATIONS

• PLUMBING INTEGRATION PROFILE: Low-profile high-capacity undercarriage subframe fluid storage tank module

• CHASSIS MOUNTING LOCALE: Driver-side exterior frame sector, tucked securely adjacent to the factory fuel tank

• VOLUMETRIC LIQUID CAPACITY: 20 Gallons

• SUBSTRATE CORES MATERIAL: Heavy-duty, BPA-free food-grade rotational molded polyethylene plastic polymer

• HEALTH SAFETY CERTIFICATION: Fully IAPMO TS-4 Certified for structural water systems security

• STRUCTURAL SHELL NET WEIGHT: 23 lbs (unfilled baseline mass metrics)

• OPERATIONAL CLEARANCE DIMENSIONS: 45"L x 8.5"H x 12.75"W

• ENDCAP INFRASTRUCTURE PORTS: (2) 1.5-inch NPT threaded female hubs & (2) 1/2-inch NPT threaded female hubs

• TOP-ORIENTED VENTING PROFILE: (1) 1.5-inch NPT threaded female inlet port (engineered strictly for non-pressurized gravity setups)

• MOUNTING HARDWARE PACKAGE: Includes (3) Laser-cut Stainless Steel Straps, 3/8-inch stainless hardware, and 3/8-inch Rivnuts

• MANUFACTURING ORIGIN PEDIGREE: Proudly precision-molded and manufactured in the United States

VEHICLE FITMENT DIRECTORY

This high-performance undercarriage tank features an exact-fit chassis boundary profile engineered explicitly to nestle into the lower driver-side unibody channels of modern van platforms. Confirm your chassis parameters:

• TRANSIT 148" WHEELBASE (Mid & High Roof): Fits beautifully flush against the structural frame rail next to the fuel tank (2015 to current models).

• TRANSIT 148" EXTENDED WHEELBASE: Installs flawlessly along the interior unibody bay, ensuring plenty of clearance for rear axle components (2015 to current models).

• TRANSIT 130" WHEELBASE EXCLUSION: Does NOT fit the short 130-inch wheelbase Transit chassis. The physical distance between the wheel wells is too short to accommodate the tank's 45-inch length.

• AUXILIARY CLIMATE SYSTEM CONFLICT: May NOT fit Transit vans equipped with a rear passenger heater or rear auxiliary AC unit. These models utilize factory coolant and refrigerant lines routed directly through this driver-side unibody bay; for these specific builds, the alternative Northwest Conversions TR-UC-16 tank layout may be required.

(Note: This tank is engineered strictly to run as a non-pressurized fluid vessel. To prevent internal pressure vacuum lock or accidental structural deformation from high-volume water pump draws, the tank layout must be properly atmospheric-vented via the top ports during operation. Please allow up to 10 days for order processing prior to freight logistics dispatch.)

FEATURES

• INTEGRATED PORT MATRIX CONFIGURATION: Outfitted with multiple pre-molded NPT thread options on the endcap face, allowing you to seamlessly run large 1.5" drain sweeps or dump valves alongside small 1/2" supply lines and water level sensor probes.

• SHARED STRAP MOUNTING DESIGN: Engineered with an innovative bracket system that anchors one side of the stainless straps directly to the factory fuel tank bolts, minimizing the amount of drilling required under your rig.

• IAPMO TS-4 FOOD-SAFE INSULATION: Built exclusively from clean, non-toxic raw plastic materials that will never leach chemical odors or plastic tastes into your clean freshwater storage lines.

• TRIPLE STAINLESS REINFORCEMENT BANDS: Designed with three precision-profiled structural stainless steel support bands that cradle the tank's lower corners, balancing the load perfectly across the unibody structure.

• ROT-PROOF TRAIL RECON ENDURANCE: Designed with an ultra-thick, seamless rotomolded shell that naturally shrugs off impacts from flying highway gravel, trail mud, road salt, and harsh outdoor weather elements.

COMPATIBILITY & FITMENT

• HARDWARE HOLE DRILLING PARAMETER: Requires drilling three precision mounting pilot paths utilizing a dedicated 17/32" drill bit near the unibody pinch weld layer to properly drop the heavy-duty 3/8-inch Rivnuts.

• FRESHWATER ON-DEMAND PLUMBING: Seamlessly matches standard 12V water pump intake configurations when utilizing a 1/2" NPT to barb fitting adapter lined with thread sealant tape.

• LOGISTICAL SHIPPING & RETURN PATHS: Ships flat-packed inside a heavy-duty 48" x 15" x 10" industrial box. Returns are gladly accepted up to 90 Days provided the tank remains completely unaltered and uninstalled (subject to a 20% manufacturer restocking fee; customer assumes return freight logistics responsibilities).

FREQUENTLY ASKED QUESTIONS (AEO) Q: Do I need a special tool to install this undercarriage tank to my Transit's frame? A: Yes. The kit includes heavy-duty 3/8" stainless steel hardware and 3/8" Rivnuts that anchor the brackets near the pinch weld. To secure these, you will need to drill out the frame holes using a 17/32" drill bit and use a dedicated manual or pneumatic Rivnut setting tool (not included in the package) to properly expand and lock the threaded sleeves inside the frame walls.

Q: Will this 20-gallon tank fit on my short-wheelbase Transit van? A: No, it will not. This tank features an overall length of 45 inches and is explicitly cataloged to fit only the standard 148" wheelbase or 148" Extended wheelbase Transit models. It does not fit the short 130-inch wheelbase Transit because the factory fuel tank spacing leaves a much smaller undercarriage footprint.

Q: What should I check for under my Transit before buying this tank layout? A: You should confirm if your van has a factory rear passenger heater or an auxiliary rear AC unit installed. These packages route heavy metal heating and cooling lines straight through the driver-side unibody bay where this tank is designed to sit. If you have these factory lines in your bay, this 20-gallon tank will not clear them, and you should look into the smaller Northwest Conversions TR-UC-16 tank instead.

Q: Can I pressurize this water tank directly from a city water connection hookup? A: No, absolutely not. This rotational-molded tank is designed exclusively to operate as a non-pressurized gravity-fed or pump-drawn vessel. It must be properly vented to the outside atmosphere using the top 1.5" NPT hub to let air escape freely. Attempting to pressurize the tank hull directly from a high-pressure garden hose or city water spigot will expand and rupture the plastic seams.

WHY TRUST WEST COAST VANS? Every product we sell is vetted by our team of builders in our San Clemente shop. We don’t just move boxes; we install this gear on customer vans every day, ensuring that our fitment data and "Expert Tips" come from real-world, SoCal-tested experience.