1981 SN Axle

I am in the process of restoring my 81 SN single axle trailer (original) and noticed that both tires are wearing on the inside. Is this a problem with the axle being out of alignment/bent or the springs needing to be replaced? If it is the axle, any recomendations on where to get one for this trailer? The axle has a drop down which matches that of the prop/fin gaurds. Also, any recomendations on where to find spings for this trailer (the springs are made up of 7 leafs)? Any help in pointing me in the right direction is greatly appreciated.

Hey Roger- Can't seem to get your link to work.

Thanks so much for the quick responses... I looked on trailerpartsdepot.com (no agri-supply here in Southern California) and was a bit confused with the different selections/types of axles. Would I be looking at a torsion axle? Seems to be the one that allows for the drop down. I also looked for leaf springs but they do not have a 7-leaf spring. Do i neeed 7 leafs if my current spring is set up like that or do I just need one that will support the weight? From what I have seen, the overall weight (boat+trailer+fuel+ski equipment) is about 3,500 lbs on an 81 SN... do I just get a apring that will support 1750 per spring? Thanks again for all the help.

I'm a slow typer, you must have posted while I was. If you live in So Cal and can't find someone to make springs,you must not be looking Like I said look around,I'm sure they could realign that axle too,it would be easier than starting over.

I would shoot for a 2000lbs spring but 1750 would work too haul it down to the local truck stop that has a scale and see exactly what it weighs so your not guess and over springing the trailer causing bounce or under springing and bending the axle.

Measure the span from eye to eye (the part of the spring that the hanger and bolt attach the trailer's frame and the leaf spring it's self) on the spring the style of the eye on each end of the spring usually they are not the same. Measure the width of the spring, measure the width, O.D and I.D. of the bushings at each end of the spring usually they are the same. You'll also want to measure the length of the hanger if it's not welded to the trailer's frame. Once you have all this info then you can order the correct spring.

Take some pictures and post them if you can that will help us direct you to the right springs for the job. Your axle might have a slight bend in it causing the tire ware but replace the springs first then you can do some string measurements and find out for sure then we can address that issue.

As long as the load rating on the springs is appropriate, the # of leafs really doesnt matter much. The length is an oddball one though- which is really the reason you may have to go custom. I ran into this issue on my #2 CC trailers.

I've attached a few pictures of the axle, springs, and tire. Is that a torsion axle that is pretty common or something specialized? The spring measures 30" on center from both eyes. I looked at agri-supply, trailerparts depot and etrailer, but none seem to have the 30" double eye spring. Just may have to have them custom made Let me know what you guys think.

I agree with Pete on the under inflation issue, But I also see a toe issue as well, drag your palm across the width of the tire outside to inside and then inside to outside, if you feel a sharp edge in one direction against your palm as you move across the width that is caused by the toe being off. I can tell you exactly how to measure it and how you can bend the axil yourself to correct the problem pretty easy fix just have to go slow and might have to do it a couple of times untill it's right.

There is no need to get all bent out of shape and worried by everyone telling you it's a special length because it really doesn't make that much of a difference, the springs are unsprung at the moment and if they where loaded you would have a longer dimension. With it unloaded you need to measure the height of the spring so you can order a new spring that will work well in this application. With the design of the shackel in the rear you have some leway on length.

You need to drop a plumb bob off of the rear shackel where the top bolt mounts to the fixed postion on the trailer now measure across a level line from the front eye bolt that is fixed to the frame and get that measurement should be longer than the 30 earlier. Once you have that then we can pick the spring.