10 DIY Wheel Well Storage Boxes for Cargo Van Conversions

Standing in an empty cargo van with a tape measure reveals a frustrating reality: the massive, awkward metal mounds of the wheel wells ruin any clean layout plans. These irregular humps take up prime floor real estate right where a bed, kitchen, or garage space needs to go. Turning this dead space into functional storage is the single most important step to unlocking an efficient, comfortable mobile home layout.

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Why Wheel Well Storage is Essential for Van Layouts

Wheel wells are awkward, non-uniform shapes that interrupt straight interior walls and limit floor-plan options. Building custom boxes over them squares off the lower half of the van, creating flat, predictable mounting surfaces for bed platforms, benches, or partition walls. Without these boxes, you end up with unusable gaps behind your furniture where dirt, gear, and moisture can easily accumulate.

Weight distribution is another critical factor in mobile builds. Liquid tanks and heavy electrical components should sit as low and central as possible to ensure stable highway handling. Placing these heavy assets directly over the rear axle inside wheel well storage boxes drastically improves vehicle traction, braking performance, and overall safety.

Finally, structured wheel well boxes create designated compartments for recovery gear, shore power connections, and plumbing manifolds. Instead of letting the “garage” area under a platform bed turn into a chaotic pile of loose gear, these boxes keep your gear organized. This keeps the center aisle completely clear for hauling large items like bikes, surfboards, or building materials.

Wheel Well Cabinet – RB Components 48-Inch Cabinet

A long-format, heavy-duty cabinet is essential to span the entire length of the rear quarter panel, providing a rigid foundation for upper structures. Without a structured cabinet, the space above the wheel well remains unutilized, forcing you to hang gear from the walls or ceiling where it can rattle free during transit.

The RB Components 48-Inch Cabinet is an absolute workhorse due to its powder-coated aluminum construction and integrated storage dividers. It features pre-cut openings for wiring and plumbing, making it an excellent hub for complex utility runs that need to pass from the rear of the van toward the front living space.

• Dimensions: 48″ L x 14″ W x 23″ H
• Material: Heavy-gauge welded aluminum
• Compatibility: Optimized for Sprinter vans but adaptable to Transit and Promaster DIY builds

Because of its rigid metal frame, installers must ensure the van wall is properly insulated and sound-deadened before bolting this unit down. Accessing the bare metal behind the cabinet after installation is nearly impossible without a complete teardown.

This cabinet is ideal for builders planning a robust power system or a permanent platform bed support on one side of the van. It is not suitable for budget builds or those who prefer the warm, organic look of natural wood cabinetry.

Storage Box – Flatline Van Co Sprinter Wheel Well Box

A clean, standardized box simplifies the build process by eliminating the need to design complex angles from scratch. It bridges the gap between raw sheet metal and a finished, professional-looking garage space.

The Flatline Van Co Sprinter Wheel Well Box offers a precise fit that hugs the factory contours of the van. Made from lightweight, laser-cut aluminum, it maximizes interior volume without adding unnecessary, fuel-sapping weight to the rear axle.

• Material: 5052 Aluminum with a textured black powder coat
• Mounting: Pre-drilled holes for secure floor and wall anchoring
• Options: Driver-side and passenger-side specific designs

While it fits modern Sprinters perfectly, owners of Transit or Promaster platforms will need to fabricate custom spacer brackets or shim the base to achieve a flush fit. The metal surface can also get cold to the touch, so lining the interior with trunk-liner felt is highly recommended to protect delicate gear.

This product is perfect for Sprinter owners who want a professional, plug-and-play metal box to house lithium battery banks or heavy recovery gear. It is not the right choice for builders on a tight budget who can replicate the shape with cheaper plywood.

Wheel Well Pod – Serg Supply Sprinter Storage Box

For many builders, a van is a home first and a vehicle second, meaning warm, organic textures are preferred over cold industrial metal. A wooden storage pod brings a high-end, residential feel to the garage or sleeping area.

The Serg Supply Sprinter Storage Box brings fine woodworking into the van garage with its CNC-milled Baltic birch construction. This pod features elegant finger-joint styling, integrated soft-close hinges, and pre-routed channels for clean wiring runs.

• Material: Premium 13-ply Baltic Birch plywood
• Finish: Ships raw and unfinished, requiring sanding and sealing
• Assembly: Flat-packed; requires wood glue, clamps, and basic assembly tools

Because it is made of natural wood, it must be thoroughly sealed with a high-quality polyurethane or polyx oil to prevent warping in damp climates. Failing to seal the interior of the box can lead to mold if wet gear is stored inside after a rainy weekend.

This is the ultimate option for DIYers aiming for a cozy, Scandinavian-inspired interior who enjoy a weekend assembly project. It is not recommended for builders who want a maintenance-free utility box right out of the shipping crate.

Integrated Tank – Northwest Conversions 22-Gallon Tank

Storing fresh water inside the heated envelope of the van prevents winter freezing while keeping the center of gravity low. A standard rectangular water tank wastes valuable space, but an integrated wheel well tank solves this layout puzzle.

The Northwest Conversions 22-Gallon Tank is specifically molded to drape perfectly over the rear wheel arch, utilizing otherwise unusable space. Its heavy-duty, food-grade polyethylene construction ensures clean drinking water and extreme puncture resistance.

• Capacity: 22 Gallons
• Ports: Multiple 1.5-inch and 0.5-inch NPT threaded fittings
• Fitment: Fits both driver and passenger sides of most modern cargo vans

Plumbing this tank requires careful planning of vent lines, gravity fill ports, and water pump placement before permanently mounting any bed platform over it. You must also ensure the tank is strapped down with heavy-duty steel bands to prevent it from shifting under the weight of sloshing water.

This is a must-have for four-season off-grid travelers who need substantial water capacity without sacrificing central living space. It is not necessary for weekend campers who rely on simple, portable water jugs.

Aluminum Cabinet – Van Wife Components Wheel Well Box

Off-road travel subjects a van’s interior to constant vibrations and chassis flex, demanding rugged cabinetry that won’t squeak or fall apart. Lightweight aluminum cabinets offer the durability needed for rough dirt roads without overloading the vehicle.

The Van Wife Components Wheel Well Box is engineered from aircraft-grade aluminum with fully welded seams to withstand extreme rattle-inducing washboard roads. It features heavy-duty compression latches that keep doors locked tight even over rough terrain.

• Material: 1/8-inch CNC laser-cut aluminum
• Access: Front-facing doors with secure locking mechanisms
• Finish: Raw aluminum or textured powder coat options

Installing this cabinet requires drilling directly through the van floor to anchor it securely, meaning proper rust-prevention paint must be applied to the exposed steel holes. Additionally, the lack of interior shelving means you will need to use modular packing cubes to keep smaller items from rattling around.

This box is built for serious overlanders and dirt road explorers who prioritize durability and zero-rattle performance. It is overkill for casual highway cruisers or those seeking a soft, fabric-centric aesthetic.

Utility Storage Box – Titan Vans Sprinter Box

Electrical power centers generate significant heat and require dedicated, ventilated housing to protect sensitive inverters, solar controllers, and lithium batteries. A standard closed wooden box can lead to system overheating and premature component failure.

The Titan Vans Sprinter Box is designed specifically to act as a self-contained utility mechanical room. It features built-in laser-cut ventilation grilles to promote natural convection airflow, along with removable panels that allow easy access to fuses and wiring harnesses.

• Design: Optimized for heavy electrical gear and battery layouts
• Ventilation: Laser-cut slots for active or passive cooling
• Access: Removable magnetic faceplates and hinged top lids

When mounting high-output inverters inside this enclosed space, you must install active 12V cooling fans to pull heat away from the electronics. Make sure to route all heavy-gauge wiring through rubber grommets to prevent the sharp metal edges of the box from chafing the cables.

This is the ideal foundation for DIYers building a high-end lithium power system who want a clean, professional mechanical compartment. It is not suitable for those looking for simple, open gear storage for wet outdoor equipment.

Soft Storage Locker – Adventure Wagon Mule Bag

Traditional rigid wooden or metal boxes can add excessive weight to a build, reducing fuel economy and payload capacity. Utilizing soft-sided lockers allows you to maximize storage volume while keeping the vehicle light and nimble.

The Adventure Wagon Mule Bag serves as a brilliant alternative or companion to lower wheel well boxes by offering lightweight, soft-sided storage. While typically mounted high, these durable ballistic nylon bags can be integrated into lower framing structures to keep gear secure and rattle-free.

• Material: 1680D Ballistic Nylon
• Capacity: Over 90 liters of flexible storage space
• Pockets: Integrated interior mesh pockets and exterior webbing

While highly durable, soft storage lacks the structural integrity to support a bed platform, so it must be paired with an independent steel or aluminum frame. The fabric can also absorb odors over time if used to store greasy tools or damp recovery gear.

This is perfect for weight-conscious builders who want modular, easily removable storage for clothing, bedding, and soft goods. It is not suited for housing heavy electrical batteries or liquid tanks that require rigid mounting.

Protective Cover – Legend Fleet Insulated Covers

Bare metal wheel wells are a primary source of road noise and thermal transfer, making the van cabin drafty and loud during long highway drives. Adding a protective cover is the first line of defense before building any cabinetry.

The Legend Fleet Insulated Cover acts as a protective, thermal-acoustic barrier that wraps directly around the bare metal humps. Its durable, impact-resistant outer skin protects the metal from cargo damage while significantly deadening road vibration.

• Material: Dual-density acoustic foam with a hard plastic shell
• Installation: Direct fit over factory wheel arches with heavy-duty adhesive
• Noise Reduction: Up to 50% reduction in rear-cabin road hum

This cover must be installed before building any custom wood or metal framing around the wheel wells to ensure a snug, insulated fit. If you plan to build tight-fitting custom cabinets, ensure you account for the extra inch of width this cover adds to each side.

This is an essential upgrade for DIYers who want a quiet cabin ride and improved climate control without building bulky wooden boxes. It is not needed if you plan to fully encase and insulate the wheel wells with spray foam and custom cabinetry.

Storage Trunk – Decked Sprinter Cargo Van System

Maximizing storage often requires a system that utilizes the entire floor area, bridging the gap between the two wheel wells with a heavy-duty platform. This approach is ideal for those who need to haul heavy cargo on top while keeping tools organized below.

The Decked Sprinter Cargo Van System creates a flat, heavy-duty raised deck that spans across the wheel wells, complete with massive pull-out drawers underneath. This rugged, weatherproof trunk system allows for heavy cargo storage on top while keeping tools and gear organized below.

• Weight Capacity: 2,000 lbs distributed load on the top deck
• Drawer Capacity: 200 lbs per drawer
• Material: High-density polyethylene (HDPE) with steel reinforcement

This system is heavy and raises the floor level by about 12 inches, which significantly reduces the standing headroom inside the van. It is also a permanent installation that makes accessing the factory floor tie-down points difficult without removing the entire deck.

This system is ideal for moto-vans, mobile workshops, or weekend warriors who need to haul heavy toys on top and secure gear underneath. It is not suitable for high-roof camper builds where standing upright is a priority.

Heavy-Duty Slide – CargoGlide CG1000 Slide Out

Reaching gear stored deep in the center aisle between wheel well boxes can be a back-straining chore, especially under a low platform bed. A heavy-duty slide-out tray brings the gear to you, saving time and physical effort.

The CargoGlide CG1000 Slide Out solves this accessibility crisis by turning the entire floor between your wheel wells into a rolling drawer. With its heavy-duty steel construction and smooth roller bearings, it allows you to pull up to 1,000 pounds of gear out of the back doors with one hand.

• Weight Capacity: 1,000 lbs (evenly distributed)
• Extension: 70% extension beyond the rear door threshold
• Locking: Multiple locking positions for safety on uneven ground

The slide assembly itself takes up about four inches of vertical space and adds considerable dead weight to the vehicle before any gear is loaded. You must also ensure the slide is bolted securely through the vehicle’s structural frame crossmembers to prevent tipping when fully extended.

This slide is a game-changer for gear-heavy travelers, mountain bikers, or those with deep “garage” layouts under their beds. It is not recommended for minimalist builds or those trying to stay strictly under gross vehicle weight ratings.

How to Secure DIY Storage Boxes to Your Van Frame

Simply screwing a wooden or metal storage box down into the plywood subfloor is a recipe for disaster in an accident. During a sudden stop or collision, unsecured cabinets can shear right off the floor and become dangerous projectiles. To prevent this, structural storage boxes must be mechanically anchored directly to the vehicle’s steel chassis.

The most reliable method is using heavy-duty Rivnuts (rivet nuts) or Plusnuts inserted directly into the van’s factory wall ribs and floor joists. Avoid using standard self-tapping screws for structural load-bearing points, as they can easily back out over time due to road vibrations. Instead, use grade-8 bolts paired with thread-locking compound to secure your mounting brackets.

When mounting wood-to-metal or metal-to-metal, always apply a thin layer of closed-cell foam tape or heavy-duty adhesive sealant at the contact points. This acts as a thermal break and prevents the constant, maddening squeaking that occurs as the van chassis flexes during transit. Regularly check and retighten these mounting bolts after the first few thousand miles of travel.

Conclusion

Optimizing the dead space around your van’s wheel wells is a crucial design milestone that sets the tone for the rest of your build. Whether you choose heavy-duty aluminum cabinets, modular wood pods, or integrated water tanks, these solutions turn structural challenges into layout assets. With the right storage strategy, your van’s garage area will transition from a cluttered catch-all into a highly organized, efficient mobile system.