15 Comments

  1. CRAIG SCANDRETT
    August 12, 2018 @ 8:23 PM

    IS THERE ANY VALID OR SAFETY REASON TO HAVE THE TRAILER AXLE ON TOP OF THE SPRING OR UNDER THE SPRING AS I HAVE SEEN THEM BOTH WAYS THANK YOU.

    Reply

  2. Jim L Richardsaon
    October 25, 2018 @ 9:01 AM

    Thanks for this great article on trailers ! Really makes sence on what axels you choose . Was going to use tork but now spring makes more sence ,
    Thanks JimR

    Reply

  3. Jack
    August 7, 2019 @ 7:07 PM

    Nice, thank you for your insights. Jack

    Reply

  4. Gus
    October 3, 2019 @ 9:26 PM

    Thanks for the great info ME. Mounting springs on angle also allows adjustment of final axle position later in the build. I’d appreciate any advice on stitch welding the angle iron buffer to the RHS chassis rail – it is full width of the RHS but only about 65% of the height of the RHS chassis rail. Also, any advice on avoiding rust between these flat surfaces of steel? Thanks, Gus

    Reply

    • The Mechanic
      October 7, 2019 @ 8:56 PM

      Stitch welding is a great solution anytime the weld joint is long but not under a lot of load — like springs on angle. For something like this, a 1″-1.5″ stitch every 6″ ought to do. Avoiding rust between the faces — There’s a lot to that, so watch for a post on that sometime in the future.

      Reply

      • Gus
        May 2, 2020 @ 9:46 AM

        Brilliant, thank you

        Reply

  5. Gus
    May 2, 2020 @ 9:59 AM

    Following on, i used 6mm thickness (~ 1/4”) angle for the the buffer, on 3mm thickness RHS chassis rail on this trailer. But I note your advice to “Make the buffer piece at least as thick as the spring mount bracket material”. The spring mounts for my next trailer are 10mm steel thickness (which many commercial trailer builders would just weld directly to the 3mm thickness SHS/RHS chassis rail). Should I really go with 10mm thickness angle to match the spring hanger thickness? What’s the principle we are trying to follow and what’s the downside to using 6mm angle for the spring mounting buffer rather than 10mm thickness angle?
    Really appreciate the advice. Thanks, Gus

    Reply

    • Mechanic
      May 2, 2020 @ 4:18 PM

      I know a lot of people do just what you say — and it works mostly. I’ve also seen trailers where the main beam around the spring mount has collapsed, or the trailer bent. I saw one the other day that I pointed out to my wife as we drove by. Anyway, read https://mechanicalelements.com/mounting-trailer-axle-springs/ for more information. Bring some focus to Figure 4. Does it have to be 10mm? No. Anything helps. Same thickness is a good rule of thumb. Good luck with your project.

      Reply

  6. Nabil
    May 9, 2020 @ 3:26 PM

    I’m building up an aluminum trailer frame with square tubing. I’m planning to use the spreader plate as shown above, out of aluminum. But the spring hardware is all steel. Would it work to do a dual stack of plates? One steel for the spring hangers to weld to. Then a second of aluminum welded to my main beam for spreading stress as well as tapping threads into to bolt the steel plate to? I’m trying to avoid bolting through the whole tubing and risk collapsing it.

    Reply

    • Mechanic
      May 11, 2020 @ 7:54 AM

      A stack is fine. I agree, don’t bolt through the beam vertically — holes weaken beams in the higher stress areas. The top and bottom of the beam are the highest stress, so bolt through the sides. Finally, make sure there is a barrier between the aluminum and steel — paint, plastic, something to avoid galvanic corrosion between the dissimilar metals.

      Reply

  7. Ivan Vuja
    May 13, 2020 @ 10:42 PM

    Thanks so much for this useful article! However, I do have a question about welding on the hangers.
    I understand that you should only weld the sides and not across, however you don’t mention if you should still tack weld the hangers in the designated tack welding holes most hangers come with at the top.
    So should you also tack weld, or would that be the same as welding across and should be avoided?
    Thanks!

    Reply

    • Mechanic
      May 14, 2020 @ 9:56 AM

      Maybe I need to write a little more to clarify that . . . . Figure 2 shows the hangers directly on the main beam. Figure 4 shows the hangers with a buffer piece between them and the main beam. You can weld all around the hangers onto the buffer piece, then weld the buffer piece to the main beams only on the sides. The recommendation is to avoid welding on the top and bottom surfaces of the main beam, not the other surrounding members. Sorry for the confusion.

      Reply

      • Ivan Vuja
        May 14, 2020 @ 10:28 PM

        Thanks for elaborating, it all makes perfect sense now! As for the buffer plate, I usually make whole and tack weld flat bars onto another surface. So from what I understand I should not be making holes for tack welds between the buffer piece and the beam, but only weld the buffer piece to the main beams on the sides. Is that right?
        Thanks!

        Reply

        • Mechanic
          May 15, 2020 @ 9:25 AM

          That’s what I recommend. The buffer piece is much larger so it gives plenty of area along the sides for firm attachment without welding across the main beam. Good luck with your project.

          Reply

          • Ivan Vuja
            May 15, 2020 @ 10:32 PM

            Perfect, thank you so much!

Leave a Reply

Your email address will not be published. Required fields are marked *