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Shortening a hot rod frame

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  • Shortening a hot rod frame

    A buddy of mine has asked if I would be interested in working on a frame for a 52' dodge truck. He wants to use a 84' dodge frame but needs to shorten it 21" in the middle and 9" off the rear.

    I guess first off is tigging this going to be a feasible solution? The frame is .156" and I recommended if he is going to do it that he needs to box the frame as well as weld a plate across the cut in the frame rail. Should the cut in the frame be diagonal? I was thinking of using ER70S-6 filler is this the right filler and what size would be the best for this? I have a Dyn 200DX can you make any recommendations for settings for this type of application.

    Thanks Guys!

  • #2
    You have the right idea boxed and a gusset plate over the cut. I wouldn't diagonal the cuts, due to alignment issues and the possibility of twisting. My guess is when you get the scraps cut you'll have a chance to test the settings, DC-140 amps-3/32"-2% ceriated tungsten, 3/32"-ER70-s6 filler should be close. Test on scrap.



    • #3
      I've been thinking about shortening a F-450 or F-550 to accept a pick-up bed (cab and chassis frames are 4" longer than a standard truck). Or possibly shortening a regular cab long bed Ford F-250 or F-350 to fit a short box (only available with long beds with regular cabs from the factory). There is a guy (weweld) on SoCals Powerstokes forum ( that has done about 3 or 4 of these mods.

      Here's a link to some of his pictures photo album.

      Here's a quote from one of his posts describing what he did. "I removed the exhaust from the coverter back along with the drive shaft,fuel tank,fuel lines and brake line. The wiring was unhooked and moved forward by the trans to protect it during the cutting. If you have ever cleaned undercoating off a frame you what fun that can be.

      After careful thought and planning I was able to mark out the cut lines on the frame. The next step was to support the frame to hold the front half of the truck in place. The back half needed to be able to move after the cut was made so I chose the old bumper jack. So before making the actual cut I took a break and went to McDonalds for lunch. After returning and not thinking of anything else I needed to do I was ready.

      With plasma cutter in hand I carefully cut the truck frame in two pieces. I then sanded the cuts clean and rolled the two pieces together for the first fit. Can you imagine that ,they fit first time. I then clamped the frame together and checked for alingment and adjusted it. I then did a two pass weld and then cut a couple of plates to put inside the frame rails. The plates where cut to length and punced with eight holes. The plates where clamped the the frame and the holes where rosette welded first and then welded top and bottom. After cooling they where cleaned and painted to prevent any rust."

      Hope this helps


      • #4
        Done alot

        Ive done a ton of these, both on tri axle dumps to cars, always 45 them, and have some one with a press brake form you a pc. of channel to go inside as tight as possible,,,Slege hammer it in , and when you weld and grind the inside, then the outside with the chanells clamped, for warpage,and to keep it strait, You should ream the holes to exactly the dia. of the grade 8 bolts u put in staggered, rule of thumb is go 12" one each end if possible,,,but some times you have to do ,the way it can be done,,Hope this helps,Jack


        • #5
          Thanks guys for your replies.

          I finally got around to starting on this project. Here are some pictures of where it stands now. I still have to weld the backer plate all the way around, finish the plug welds and then box at least this section of the frame.


          • #6
            I realize my post is more than likely to late but I would not verticle weld the back plates,or at least keep the verticle welds on the ends to a minimum.
            To all who contribute to this board.
            My sincere thanks , Pete.

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