leaf springs reldocate

admin

I have a question I couldn't find an answer on the trailer building thread......I have a 5 ft axle and leaf springs from a welder trailer.  Would it be ok to move the springs out to a wider center.  They are now at 3 ft.  The pin that goes up through the spring stack sits in a hole in the square tube axle. It is a blind hole so to say....there must be a plate in front of the hole up inside the tube axle.  If I just drill new holes at the wider spacing I want will that weaken anything? My new holes wouldn't have the plate behind it...what is it for anyway.  Any help from trailer guys would be much appreciated!
Reply:My 1st though is that the plate may be to keep water out of the axle so it doesn't rust out from the inside or fill with water and freeze and split. It might also be to spread out the load to a larger area so the tube doesn't collapse from localized stresses. Picts would help..No government ever voluntarily reduces itself in size. Government programs, once launched, never disappear. Actually, a government bureau is the nearest thing to eternal life we'll ever see on this earth! Ronald Reagan
Reply:It's odd that the springs are that far in.... typically they recommend that the springs be as far outward as possible. The further in with them you go the more capacity you lose.
Reply:If I were to do this I would find a piece of plate the thickness of the head on the spring bolt. I would just drill the hole in the plate only and use it as a spacer. You could then tack it to the axle if needed.
Reply:The "pin" that goes through the spring stack is the "center bolt".  Its purpose is for 2 things.  First, it keeps all the spring leaves oriented on their proper center lines. Second, in conjunction with the hole in the axle, it keeps the center line of the spring stack oriented at the proper "loading point" of the axle tube so the axle can't shift. An axle that moves off the center will not track straight going down the road.  DO NOT drill a hole in the axle tube to act as an index hole for the dowel head of the center bolt. Water will be able to enter the tube and as already mentioned, freezing will rupture the tube and the tube will rust away from the inside out.As was mentioned in a post above, fabricate new mounting pads out of appropriately thick plate and weld the plates to the axle tube.Pictures would be nice.  That way we could get an accurate idea of the other aspects of the set up such as u-bolts and spring caps.  Plus we might be able to figure out why the springs were placed so far inboard to begin with.Last edited by walkerweld; 11-17-2013 at 09:39 AM.
Reply:OK, I missed the part in the opening post about the axle was originally on a welder application.  That explains the extreme inboard mounting.  The welder frame comprises a narrow width perimeter but the wheel track must be wide to make the towed assembly stable in the vertical plane, otherwise the first tight turn at speed would flip the welder over.With that in mind, the second thickness of material you see below the outer surface of the axle tube might possibly be a second tube inserted into the outer tube to reinforce the total axle beam because of the inboard mounting point needed to mate the welder to the axle.You are planning to use this axle under a different vehicle or bed???You will still be good if you fabricate new spring pads out of plate.
Reply:New spring seats are available from most any place that sells trailer parts. Northern has them or you can order them from the place in the link, they are on the third page down. The seat keeps the axle from turning and gives the spring a flat spot to sit on. You really don't want to drill into the axle or bolt the springs to a round axle. Make sure you keep them oriented correctly on the axle, that is how the toe-in is set.http://www.redneck-trailer.com/Porta...nt/files/B.pdf
Reply:Thanks for the info guys.  I knew there had to be a reason...I just didn't know what it was.  I will try to get a pic up. I am actually building a channel frame similar to a previous post (pic) to set the sa 200 on, then bolt the spring mounting brackets to the under side of the channel. Does 3/8 plate sound reasonable for new mounting pads?
Reply:If the thickness of the dowel head on the spring center bolt has a 3/8" or less profile (viewed from side), then yes, 3/8" plate will be OK.  You just don't want the center bolt to rest on the axle tube.  You want only the spring to rest on the spring pad.