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Houston_Remodel's avatar
Apr 19, 2016

DIY generator box for a honda 3000

The available factory made aluminum diamond plate boxes run $1200. I'm far too cheap to buy one. Time for a Macgyver moment.

After reading the specs on the factory model, I went to Home depot and found this tool storage box for $60. It's a little longer, but the genny still fits in.

To attach the box to the truck and prevent / deter theft, I elected to use the hole in the middle of the bed of the truck meant for the 5th wheel attachment. It is a 2 3/8" diameter hole, 4 inches deep, through a heavy steel frame which is bolted to the truck. Strong enough for a 5er, strong enough for this job.

29 Replies

  • Wait I read it again and I understand you used a long union nut to hold the ends of the two bolts. Something like this.
    Link
  • Awesome job, I bet it makes that already quiet generator even quieter.
    On question though. I don't understand the attachment of the wooden plug. Is there a bolt from the generator going down and a bolt from the bottom going up? Do the two bolts meet in the middle?
  • A rotary switch $14 was added to allow for either the generator OR the shore power. The generator / rotary switch is tapped in after the PI surge protector.


    The power inlet on the TT was purchased along with the cord noted above.
  • upper wood plug detail

    The bottom 1.5" has the full sized hole for the female nut. The upper section has room for only the carriage bolt. The sections are screwed together to allow everything to be taken apart when the genny goes in for repair.

  • The lid needed to be notched a little to accommodate the gas cap on the genny. I used an inside pipe cutter to remove the box lid ribs.

    The bolt sticking through the box feeds into a wooden plug, the width of the hole in the bed of the truck. To keep this plug in place, a 1/2" female union nut was let into the bottom and screwed onto the carriage bolt about half way. The whole thing is tightened to the bottom of the job box, letting the plug and female union nut stick out about 1/2" as the hole in the truck sets about 1/4" below the bed of the truck. This gives me a little room to feel when the plug hits the hole and centers itself.

    A 3.5 inch galvanized steel bolt is threaded through a locking washer, a piece of flat steel* with a hole in it, then another 1 1/2 inch wooden plug to center the whole unit from the bottom. The bolt assembly is threaded up through the 5th wheel hole into the female union nut, then tightened with the same impact driver and socket as the stabilizer legs.

    * The steel is 2 inches wide, 8 inches long and 1/4 inch thick to act as a giant washer.

    The genny is now bolted to the truck, can be used in the rain, and while traveling.

    The total cost was $169, saving around $1130, and enjoyed the experience.



  • The exhaust is another roof vent from home depot $20

    The cord to the trailer was bought from Amazon, $92 which included the inlet box for the trailer. This shouldn't figure into the cost as I would have had to buy them anyway but thought to include them so y'all have an idea of the total cost.

    The cord was notched into the side, just below the water tight lid.

    8 holes were drilled in the bottom to let any rain water or spilled gasoline or oil escape.


  • The genny was set into the box, with the bolt sticking through the hole about one inch.

    To get fresh air in, the factory specs a 665 CFM 12v fan. I found one on Ebay for $20. A 9 inch hole was cut in the side of the box. That hole was covered with a roofing vent cover from Home Depot $31.

    The gaps were filled with backer rod, and everything was sealed with a silane caulking which is waterproof.


  • The 2x2 metal frame was removed from the bottom of the generator. This made it low enough to add a 3/4" thick piece of BC plywood bolted into the bottom of the generator using the factory supplied 6 threaded bolt holes.

    The plywood has a cut out to accommodate the pan on the bottom of the genny.

    A hole was drilled in the center to allow for a 1/2" galvanized carriage bold to be dropped through the plywood. This bolt is what attaches the plywood to the truck frame. The plywood is attached to the genny. The box is sammiched in between.