Transfer Flow 40 Gallon Diesel Auxiliary Tank & Toolbox System 1
Transfer Flow 40 Gallon Diesel Auxiliary Tank & Toolbox System 2Transfer Flow 40 Gallon Diesel Auxiliary Tank & Toolbox System 3Transfer Flow 40 Gallon Diesel Auxiliary Tank & Toolbox System 4Transfer Flow 40 Gallon Diesel Auxiliary Tank & Toolbox System 5Transfer Flow 40 Gallon Diesel Auxiliary Tank & Toolbox System 6Transfer Flow 40 Gallon Diesel Auxiliary Tank & Toolbox System 7
Add Fuel Level LCD Screen?:

Lead Time:  1-3 Days
Ships From: California, Tennessee


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Model: TF-0800116188
Manufacturer: Transfer Flow

This is the Transfer Flow 40 Gallon Diesel Auxiliary Tank & Toolbox System. The all-in-one auxiliary fuel tank and tool box combo is the best of both worlds, providing more fuel and secure storage for all your adventures. Our 40-gallon fuel tank and tool box combo sits nearly flush with most pickup bed rails and won't interfere with most standard fifth wheel hitches. With 6 cubic feet of storage space and locking paddle handles, you can rest easy knowing your cargo and fuel is secure.

The auxiliary system is computer-controlled by our patented TRAX 4 operating system with patented AutoTrans technology. Computer-controlled automatic fuel transfers mean worry-free operation, and much safer and more reliable operations than gravity fed systems. Based on the capacity of your vehicle's main fuel tank and the capacity of the Transfer Flow fuel tank, the TRAX 4 system will transfer fuel at predetermined fuel levels while the vehicle is in operation.

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 our TRAX 4 app with your auxiliary tank but still want to know how much fuel you have, Transfer Flow offers an 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. This item is sold separately.

Transfer Flow fuel tanks are built from ReliaSteel, high-yield U.S. aluminized steel; and powder coated black for superior corrosion resistance and strength.


  • Recommended for drivers who want extra fuel capacity and a safe place to store their gear
  • TRAX 4 computer-controlled automatic fuel transfers for worry-free operation with exclusive AutoTrans technology
  • Perfect for RVers, contractors, and outdoor enthusiasts
  • Comes complete with all components needed for installation
  • Built from ReliaSteel, high-yield U.S. aluminized steel for superior durability and strength
  • Powder coated black for a durable satin black finish
  • 6 cubic ft. of storage space (Storage dimensions: 59" L x 18" W x 9 3/4" H)
  • Gas-filled shocks for easy opening and closing
  • Stainless steel locking paddle handles
  • Baffled to prevent fuel sloshing
  • 6 year, unlimited mile warranty
  • Made in the USA
  • If you want to get your hands dirty, you can easily install the fuel tank yourself. Our tank systems come with comprehensive step-by-step instructions to make installation a breeze. We also have installation videos on our YouTube channel to walk you through each step of the process.

Fuel Type: Diesel
Dimensions: 59"L x 21"W x 21"H
Fits: 1999-Current Dodge Ram, 1999-Current Ford, 2001-Current GM/Chevy
NOTE: Product dimensions include 3" in width for the mounting brackets.

NOTE: If you have a 2010-2012 RAM Mega Cab Short Bed - an additional Filler Neck Tee Kit is required for $74.95.
If you have a 2001-2004 GM Pickup - an additional Filler Neck is required for $179.39

User Guides & Manuals

PDF  TRAX-4 Users Guide

PDF  TRAX-4 Installation Manual

Transfer Flow
Transfer Flow Warranty Details:

Transfer Flow fuel systems and parts are covered by a Six (6) year unlimited mile warranty against defects in material and workmanship throughout the U.S. and Canada from the unit purchase date by the original purchaser for the original vehicle the unit was installed in.

Warranty will not apply when product failure is caused by conditions beyond the control of Transfer Flow, such as:
  • Malfunction due to incorrectly ordered product
  • Damage from misuse, negligence, or failure to provide reasonable and necessary maintenance
  • Damage caused by improper installation
  • Damaged caused in shipment or improper handling
  • Damage caused by contaminated fuels or fuel additives
  • Product modification or alteration
  • Products made from pickled and oil material are not covered under warranty for corrosion
Any action against Transfer Flow for breach of the warranty must be commenced within one (1) year after the cause of action has accrued.

Any action against Transfer Flow for breach of the warranty must be commenced in the Superior Court of Butte County, State of California.

For specific information regarding part exceptions, exclusions and limitations, warranty claim procedures, and federal regulatory provisions, please read our full warranty details on our warranty page.

INC 5000 Award!
Inc 5000 - Award - 2023 has been awarded a ranking with the INC 5000 - 3 years in a row - of the fastest growing private companies in America!