Where to Mount the Trailer Axle

admin

Goodevening everyone!! I'll just ask you to hold on for a second as I finish... putting on... *zip* this here... flame suit... *click*Alright, now thats out of the way ...I've got another trailer building question here... I've gotten the stiffener all SKIP WELDED in place (thanks for the advice, guys  ) And so now I'm working on installing the axle. I got the leaf spring hangers all welded in place and the axle I'm using has a 3" diameter, very heavy duty. I know its overkill, but hey, it was cheap...And the leaf springs are the smaller 2,000 pound ones if that makes a difference.Anyway, I got the big axle bolted to the little leaf springs and I thought to myself "wow, thats not a lot of suspension travel" theres only like 3-4 inches which isnt good for rough roads and potholes...So, I'm thinking of mounting the axle UNDER the springs instead of on top of them. Almost every trailer I've ever seen has the axle "inside" the area between the springs and the frame, why is that? I understand ground clearance might be why... I'd almost like to raise this frame up... I mean, the trailer isnt "too" low to the ground, but I wouldnt want to build it any lower.Long story short, should I mount this axle UNDER the springs or ON TOP of them? Are there any compelling arguments in favor of one or the other, or is it "six of one and a half dozen of the other?"Thanks guys...[Account Abandoned 8/8/16 Please Do Not Attempt Contact Or Expect A Reply]. See you on YouTube! -ChuckE2009
Reply:Just my opinion but usually 3 to 4 inches is quite a bit and a sufficient amount of travel. That's if it's say 3" from the top of the axle to the bottom of the frame. Depends a little on the type of hanger arrangement tho. If you're doing a dual axle affair or standard shackle mount and not slippers you're probably good to go."The things that will destroy America are prosperity at any price, peace at any price, safety first instead of duty first, the love of soft living and the get rich quick theory of life." -Theodore Roosevelt
Reply:The choice of hanging the axle above or below the springs is simply a decision of the bed height. Is the center of the axle 60% from the front of the trailer bed?ChrisAuction Addict
Reply:3-4" is plenty.  I've built at least one trailer with 2" clearance without it ever bottoming out.My name's not Jim....
Reply:.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:Attachment 494531Attachment 494521Backed my CATMA over your CARMA oops clusmy me  What would SATAN do ?? Miller Trailblazer 302 AirPakMiller Digital Elite  Optrel Welding HatArcair K4000Suitcase 12RC / 12 VSHypertherm PM-45Rage 3 sawRusty old Truck
Reply:Springs under the axle are preferred for a lower center of gravity and also less lateral force on the spring hangers and anchor points.   the only reasons to do spring over is for clearance issue or to get the trailer level in the case of a 5th wheel for example on some 4x4 or lifted trucks.   Drop hitches are preferred for travel trailers though I have see quite a few travel trailers with spring over done to them... also the 60/40 rule applies in axle position from the tongue of the front of the trailer.  Being this is a fixed weight trailer with a BBQ,  if you can estimate the total weight,  get a bathroom scale which usually goes to 300lbs and place it under the tongue.  then put a block of wood to support the trailer at the ball and support where the axles go with 2 other blocks.  if u get a good total weight estimate,  figure out what 10-20% is and move the wood blocks until you get the right amount of weight showing on the scale.  for a light trailer I would go with 20% a bit more weight on the hitch is better than not enough...here is one video but im trying to find the other one by the new CEO of Uhaul..  very clearly demonstrates importance of correct tongue weight or in your case axle placement I have experienced incorrectly or overweight trailers/ tow vehicles personally, I can tell you its something that will make you need a change of pants and never want to experience again.Tiger Sales:  AHP Distributor    www.tigersalesco.comAHP200x; AHP 160ST; MM350P,  Spoolmatic 30A; Everlast PowerTig 185; Thermal Dynamics 60i plasma.  For Sale:  Cobra Mig 250 w/ Push-pull gun.  Lincoln Wirematic 250
Reply:Most people center the axle under the box spring.When I rebuilt my northern tool trailer (converted it from cheap-o bolt together to fully welded) I moved the axle from the middle of the box frame to closer to 2/3 of the way back. Gets the tongue weight you need with out even having to think about it.old Miller spectrum 625 Lincoln SP-135 T, CO2+0.025 wireMiller model 250 and WP-18V torchCraftsman 100amp AC/DC and WP-17V torchCentury 115-004 HF arc stabilizerHome made 4 transformer spot welderHome made alternator welder
Reply:Springs on top, or springs on the bottom, it's your choice. Ride height is the usual reason for the decision. What height works best for you when you are putting the trailer to use for its intended purpose? Suspension travel on a trailer is a good question. I suppose they are normally low travel to retain good stability, imho. Longer and thinner leaves are more flexible, trailer springs are anything but. You could fit a set of rear mini-truck springs underneath if off-road will be the norm.City of L.A. Structural; Manual & Semi-Automatic;"Surely there is a mine for silver, and a place where gold is refined. Iron is taken from the earth, and copper is smelted from ore."Job 28:1,2Lincoln, Miller, Victor & ISV BibleDanny
Reply:The rule of thumb is the tongue should have 10% of the gross weight of the trailer.  Bathroom scale is a good idea, or just measure the load carrying bed of the trailer and move the axle rearward about 10% of that length.  Don't include the tongue length in this calculation.  A longer tongue makes backing up easier compared to a short one.  Mounting the axle over or under affects two things.  Mounting springs over the axle gives more travel and higher ride height, mounting the springs under gives the opposite.  If you have a heavy duty axle and tires, get appropriate springs to go with that axle.  If you are changing the over/under mounting of the springs, be sure to remove the spring mounting brackets on the axle and move them 180 deg. on the axle.  Most axles are slightly pre-cambered (pre-bent) in the middle and are designed to straighten out as they are loaded.  Good luck with your trailer, I am confident with your dedication and welding skills, you will build an excellent one."The reason we are here is that we are not all there"SA 200Idealarc TM 300 300MM 200MM 25130a SpoolgunPrecision Tig 375Invertec V350 ProSC-32 CS 12 Wire FeederOxweld/Purox O/AArcAirHypertherm Powermax 85LN25
Reply:I'm just wondering how fast you are allowed to drive a trailer-designed-by-the-seat-of-your-pants on open road in the US? Don't you have rules and regulations, vehicle inspection or something like that?
Reply:Originally Posted by Pete.S. Don't you have rules and regulations, vehicle inspection or something like that?
Reply:Originally Posted by Pete.S.I'm just wondering how fast you are allowed to drive a trailer-designed-by-the-seat-of-your-pants on open road in the US? Don't you have rules and regulations, vehicle inspection or something like that?
Reply:Originally Posted by DSWIt's one of the reasons so many of us harp on building trailers from scratch. In many cases there really is no regs that would stop someone with zero knowledge from simply tacking a few bed frames together and adding an axle and calling it a "trailer" and putting it on the road. It's scary when you think about it. I've literally seen trailers going down the road shedding pieces and no one stops them.
Reply:Originally Posted by mad welder 4Have you seen the trailers at lowes/homedepot and northerntool/harborfreight/tractorsuppy lately?They are made from what we would describe as bed frame steel, they are so flimsy that the wooden decking is the majority of the structure and that's fine, as long as the wood doesn't rot. I personally don't like that design, to me the decking should be nothing more than decking.At least I make my trailers out of I-beam and heavy really heavy C-channel that used to be used to be concrete forms.