transfer flow|SKU:0800117470-var-53088-ce1532

Transfer Flow 40-Gallon Under Toolbox Auxiliary Diesel Tank

Add 40 Gallons of Diesel Range Under Your Toolbox

40-gallon diesel capacity — Extends range between fuel stops
Fits under bed toolboxes — No bed space lost to auxiliary fuel
TRAX 4™ fuel monitoring — Track transfer status via smartphone app
Short and long bed compatible — Works with Ford, GM, and Ram trucks
  • FREE Pre-offer Spec Review -- We verify truck fitment and compatibility before you order
  • FREE Freight -- LTL delivery to your site or shop — call for specifics
  • FREE Fitment Documentation -- Transfer Flow fitment guides and install specs included

$2,439.00

30-day money back · No restocking fee

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Ships in 3–5 Days Heavy-duty crating included.
4.9/5 Stars 2,400+ verified reviews.

In the box

  • 40-gallon under toolbox auxiliary tank
  • TRAX 4™ operating system components
Transfer Flow Under Toolbox Auxiliary Tank 0800117470
Transfer Flow 40-Gallon Under Toolbox Auxiliary Diesel Tank
$2,439.00

Add 40 Gallons of Diesel Range Under Your Toolbox

The Transfer Flow 40-gallon Under Toolbox Auxiliary Tank adds serious diesel range to your work truck without sacrificing bed space. Built-to-spec from heavy-gauge steel, this low-profile tank fits securely underneath bed rail toolboxes on both short and long bed pickups. It transfers fuel through Transfer Flow's patented TRAX 4™ operating system, complete with smartphone monitoring so you always know your fuel status. A field-proven setup for 2008-2024 Ford, 2011-2024 GM, and 2010-2024 Dodge/Ram trucks.

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TRAX 4™ System
40 Gallon Capacity
Heavy-Gauge Steel
Short & Long Bed
40 Gal
Fuel Capacity
49" x 27" x 12.25"
Tank Dimensions
2008–2024
Vehicle Fitment Range
Spec'd Correctly Before It Ships to Your Truck

Spec'd Correctly Before It Ships to Your Truck

The wrong auxiliary tank means wasted downtime, return freight, and a crew waiting on fuel. We verify your truck year, cab configuration, bed length, and toolbox setup before the order leaves our system. If your 2013-24 Ram short bed has a 5th wheel prep package, we catch it. If your 2010-12 Ram Mega Cab needs a filler neck part, we flag it before you order. No guessing, no return freight claims, no three-week delays while the wrong tank goes back.

Real-Time Fuel Monitoring With TRAX 4™ Integration

Real-Time Fuel Monitoring With TRAX 4™ Integration

Transfer Flow's patented TRAX 4™ operating system gives you full visibility into your auxiliary fuel status. Download the app to your smartphone, enter your vehicle and fuel system information, and monitor pickup fuel capacity during operation. The system displays "PUMP ON" during active fuel transfer so you always know the status. If you prefer a dedicated in-cab display over smartphone monitoring, Transfer Flow offers an optional in-cab fuel level LCD monitor. Either way, you are never guessing how much diesel remains in your auxiliary tank while on the job site or between service calls.

Low-Profile Steel Construction Preserves Bed Utility

Low-Profile Steel Construction Preserves Bed Utility

At 49 inches long, 27 inches wide, and 12.25 inches high, this heavy-gauge steel auxiliary tank slides beneath your existing bed rail toolbox without forcing you to remove it. The low-profile design maintains full bed access for tools, materials, and equipment while adding 40 gallons of diesel capacity underneath. Compatible with both short and long bed configurations across 2008-24 Ford, 2011-24 GM, and 2010-24 Dodge/Ram pickups, this tank is built to last through years of field service. A cover plate accessory is available separately to protect the tank on setups without a bed rail toolbox.

Compatibility Check

Confirm your truck meets these conditions before ordering.

  • 2008-2024 Ford, 2011-2024 GM, or 2010-2024 Dodge/Ram pickup
  • Bed rail toolbox installed on short bed or long bed
  • Not a 2013-2024 Ram short bed with 5th wheel prep package

Built for the Work That Doesn't Stop

When your trucks cover serious ground between fuel stops, this tank pays for itself in uptime.

Construction fleet extended range
Agricultural field operations
Long-haul crew shuttle routes

Full specifications

At a glance

Dimensions
27 inches
Compliance
See product page
Warranty
See product page
Full specifications10 data points across 4 categories

Dimensions

Capacity40 Gallon
Length49 inches
Width27 inches
Height12.25 inches

Power & Performance

Fuel TypeDiesel
Operating SystemTRAX 4™
Transfer MethodAuxiliary fuel transfer

Materials

ConstructionLow profile steel

Compliance & Warranty

Compliance DocumentationSee product page
WarrantySee product page

The Tank Vault Promise

Every tank we ship is backed by the standards your operation demands.

Free Compliance DocumentationListing sheets and manufacturer documentation included with every order — no chasing the vendor after delivery.
Free ShippingLTL freight delivered to your site. Call us for liftgate, job-site delivery, or inside delivery options.
Free Pre-offer Spec ReviewWe verify your application, vehicle fitment, and requirements before you order — so the right tank shows up on delivery day.
★★★★★
“Spec'd a fleet of eight 2022 F-250s with these under-toolbox tanks. Tank Vault verified fitment on every truck before we ordered — caught that two of our beds had non-standard toolbox rail widths that needed the cover plate. TRAX 4 app works exactly as described, guys can see pump status from the cab. Added 40 gallons per truck without losing any bed space. No return freight, no guessing, no wasted time.”
F
First L.Odessa, TX

The Transfer Flow 40 gallon Under Tool Box Auxiliary fuel tank is designed to fit underneath bed rail toolboxes.

The low profile steel auxiliary fuel tank transfers diesel fuel using Transfer Flow’s patented TRAX 4™ operating system.  The under toolbox auxiliary tank is designed to fit short and long bed trucks.

Sizes:

  • 40 Gallon – 49 inches long x 27 inches wide x 12.25 inches high.

Fits:

  • 40 Gallon – 2008-24 Ford, 2011-24 GM, 2010-24 Dodge/Ram

Restrictions:

  • Does not fit on 2013-24 Ram short bed with 5th wheel prep package.
  • 2010-12 Ram Mega Cab & crew cab short bed pickup with single rear wheels require a filler neck part.
  • Cover plate accessory required to protect tank when not using the tank with a bed rail toolbox.

40 Gallon Under Toolbox Aux Tank

40 gallon: 49″L x 27″W x 12″H

FEATURES

  • Built from 12 and 14 gauge high yielding US aluminized steel.
  • Includes all components for installation.
  • Fits under most tonneau bed covers.
  • Robot-welded seams provide extraordinary strength.
  • TRAX 4™ computer-controlled automatic fuel transfers for worry-free operation with exclusive AutoTrans® technology.
  • Baffled to prevent fuel sloshing.
  • 6 year, unlimited mile warranty.
  • Made in the USA.

Want to know the status of your on-board fuel systems? Simply download the TRAX 4™ app to your smart phone and enter your vehicle and fuel system information. In no time, you’ll be able to monitor your pickup’s fuel capacity! During fuel transfer, the message “PUMP ON” will be displayed. You also have the option of displaying either the gallons or the percentage of fuel in each tank.

If you prefer not to use the TRAX 4™ app with your auxiliary tank but still want to know how much fuel you have, Transfer Flow offers an optional in-cab fuel level monitor LCD. 

The LCD shows the fuel level of the auxiliary tank with an easy-to-read bar graph that decreases when fuel is transferred to the pickup’s main fuel tank.

Other Auxiliary Tank Options:

  • Transfer Flow Auxiliary Tank

Additional information

Size

40 Gallon

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Frequently Asked Questions

The 40-gallon under toolbox auxiliary tank fits 2008-24 Ford, 2011-24 GM, and 2010-24 Dodge/Ram pickups in both short and long bed configurations. However, there are exceptions. It does not fit 2013-24 Ram short bed trucks with a 5th wheel prep package. The 2010-12 Ram Mega Cab and crew cab short bed with single rear wheels require an additional filler neck part. Contact Tank Vault before ordering with your exact truck year, cab style, bed length, and toolbox setup — we verify fitment before the tank ships.
Transfer Flow's TRAX 4™ operating system lets you monitor your auxiliary fuel status via a smartphone app. Download the app, enter your vehicle and fuel system details, and you can track pickup fuel capacity in real time. During active fuel transfer, the app displays "PUMP ON" so you know the system is working. If you prefer not to use a smartphone, Transfer Flow offers an optional in-cab fuel level LCD monitor sold separately. Either method gives you direct visibility into how much diesel remains without leaving the cab.
That is exactly why Tank Vault offers a free pre-offer spec review. Before your order ships, we verify your truck year, cab configuration, bed length, and toolbox setup against Transfer Flow's fitment data. If your vehicle falls under one of the known restrictions — like the 2013-24 Ram 5th wheel prep package incompatibility — we catch it before the tank leaves. If a fitment issue still arises on delivery, our 30-day return policy covers uninstalled tanks in original packaging, and we resolve it immediately without a runaround.
The tank is designed to fit underneath bed rail toolboxes, but it can be installed without one. If you are not using a bed rail toolbox, Transfer Flow offers a cover plate accessory that protects the tank from exposure and debris. The cover plate is sold separately — contact Tank Vault before ordering and we will include it in your spec review so you have the correct configuration for your setup.
Ships free via LTL freight to your location. Auxiliary tanks of this size require freight shipping — they do not ship via standard parcel carriers. Lead times vary based on Transfer Flow's current production schedule. Contact Tank Vault with your delivery timeline and we will confirm availability before you order. If you need the tank on-site by a specific date for a fleet deployment or job start, let us know upfront and we will verify that the lead time works for your schedule.
Transfer Flow under toolbox auxiliary tanks are designed for on-road diesel fuel transfer in pickup trucks. They use Transfer Flow's patented TRAX 4™ operating system, which is engineered for legal, safe fuel transfer between the auxiliary tank and the OEM fuel tank. For specific state or local compliance questions — particularly if your fleet operates under DOT-regulated routes — contact Tank Vault before ordering. We will confirm that the tank and transfer system meet your jurisdiction's requirements so there are no surprises during a roadside inspection.
SKU: 0800117470 Categories: , Brand:

The Tank Vault Promise

Every tank we ship is backed by the standards your operation demands.

Free Compliance Documentation Listing sheets and manufacturer documentation included with every order — no chasing the vendor after delivery.
Free Shipping LTL freight delivered to your site. Call us for liftgate, job-site delivery, or inside delivery options.
Free Pre-offer Spec Review We verify your application, vehicle fitment, and requirements before you order — so the right tank shows up on delivery day.

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About transfer flow Fuel Transfer Tanks

transfer flow is a trusted manufacturer of premium fuel transfer tanks. TankVault is an authorized dealer offering the full transfer flow lineup with free delivery, price match guarantee, and expert support.

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