Auxiliary fuel/toolbox for 5er rig

**oldenkam** · 03-06-2017, 06:27 PM

Looking for recommendations on a aux fuel/toolbox combo that will work with a 5er hitch. I have a 2016 Chevy Duramax 3500 DRW long bed with the B&H Companion so I think I have plenty of room. Thinking gravity feed would be fine, 60 gallon minimum and flush with the bed rails. Look forward to your replies.

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**Lenwhite** · 03-06-2017, 09:00 PM

Originally Posted by oldenkam

Looking for recommendations on a aux fuel/toolbox combo that will work with a 5er hitch. I have a 2016 Chevy Duramax 3500 DRW long bed with the B&H Companion so I think I have plenty of room. Thinking gravity feed would be fine, 60 gallon minimum and flush with the bed rails. Look forward to your replies.

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Decided to go the larger main tank route. Put a 55 gal tank on my F250 and had dealer change setting on computer so the gauges all read correctly. Keeps the bed clear for "stuff" which I prefer.

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**oldenkam** · 03-06-2017, 09:37 PM

Originally Posted by Lenwhite

Decided to go the larger main tank route. Put a 55 gal tank on my F250 and had dealer change setting on computer so the gauges all read correctly. Keeps the bed clear for "stuff" which I prefer.

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I have looked at that option, but we can run 600 mile days and I need more fuel getting 9-10 mpg. Also like the fact of having a tool box to secure some of the extras we have onboard is a plus. We're pulling a Momentum 397th at 18to 20k lbs

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**Lebondj1** · 03-07-2017, 11:16 AM

I have a Ford F350 short bed with a Bakflip folding cover. I wanted to put in the 60 gallon RDS combination box (below the rails) but the lid would interfere with the truck cover when opening so I just purchased the 60g aux tank. Connected with a solenoid valve that switches with the inside upfitter switches. Works great. When the aux tank is filled it fills the truck tank faster than the truck uses fuel. As it empties the fill is slower. It was easy to install and Northern has them discounted sometimes.

**Bamaman** · 03-07-2017, 02:37 PM

You can Google truck toolbox with fuel tanks and come up with a bunch of them. Northern Tool also has some on their online catalog including dimensions. It'll have to clear your fifth wheel hitch which is essentially mid way in the bed and 1 inch toward the front.

I too would prefer one that fits below the top of my bed. It's also nice to have the electric pump built into the tank to quickly offload fuel into the OEM tank

**oldenkam** · 03-07-2017, 04:28 PM

Northern tool keeps coming up here so I'll certainly look at the RDS. I have heard of a gravity feed option that keeps the main tank full until the Aux runs out. I don't care that the gauge would stay on full until the Aux was empty and really don't want to have to wire a switch into the cab. Anyone used something like I am describing?

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**WE-C-USA** · 03-07-2017, 05:29 PM

I know this is my first post, and I may have brand loyalty. But a Transfer Flow aux tank has been the best thing I've added.

**bailer6334** · 03-07-2017, 05:41 PM

When I had my DMAX 3500 and 5er I had the 60gal Transfer Flow also. Never had any trouble with it. That said it was not the cheapest on the market either.

**gordofuchs** · 03-07-2017, 06:42 PM

When we started this adventure three years ago, I was able to locate an auxiliary fuel tank/tool box, used. I will have to check the make and brand. It had a high volume 12 volt pump that had been used to fuel equipment. I removed it, and just use a gravity feed to the filler tube of my truck. I installed a simple shutoff valve in the feed line. I believe the fuel capacity is close to 90 gallons. The tool box is about 6 inches deep. It sits about 1 or 2 inches below my bed rails, allowing the use of a bed cover when not towing. I love the way the setup works and if I had to do it over, I wouldn't change a thing. With both tanks filled, my capacity is around 125 gallons.

Gordo Fuchs
Presently in St. Augustine, Florida

**kanatachris** · 03-07-2017, 06:54 PM

I use a RDS 60 gallon combo tool box #72644 at Northern Tool. I also use a Bak Flip tonneau cover. The tool box lid was about 1/4" too high. I took the top off the tool box. Now there's about 1/8" clearance between the inside of the tonneau and the top of the edges on the tool box. Fits perfectly. The clearance is such that even when we're pulling the trlr in the rain with the cover folded back on itself but not up against the back window, not a drop water has ever entered the tool box. My only issue is in the winter having to open the tonneau all the way to fill the tank. Fortunately, I don't drive the truck much in the winter, so it's really not that big a deal.