Trailer Spring Mounting ???

[charlez]

I am about ready to build my new trailer. On these double eye springs, where does the rear mount go? Should it be straight up, slightly forward, slightly back??

[Skipper]

The hanger eye center should be a 1/4 inch shorter than the spring eye center.

[Sandy]

The hanger eye center should be a 1/4 inch shorter than the spring eye center.

So here's a just for fun question. Should that be shorter after it's bolted to the perch or just like it is out of the box? Or put another way, won't that spring set shown flatten out somewhat when it gets sucked down??

Curious.

[TEK]

Take a tape and go to the rental yard and look at theirs.

[Skipper]

You can measure someone elses but make sure you ave the same exact spring that they have. To be really sure call the manufacturer or talk to the guy who sold you the set and he should be able to tell you exactly. I always go 1/4 inch less than the spring eye centers. Go bigger than the springs and they want work right. Go to close with the hangers and the springs will flatten out flatten out.

[triptester]

Dexter axle or Hammerblow have sites with good info. My preference has been to use a diamention 1/2 inch less than the eye to eye measurement .

[243]

Shackle location determined when loaded or unloaded?

[MAC702]

unloaded. Maximum "loading" occurs during compression while traveling.

[Assassin]

1/2 to 1" forward towards the front hanger, was trailer mechanic for 3 yrs at Canada's largest spring manufacturer.

[theonlybull]

i find it works better the opposite way, 1/4 to 1/2" back, on an unloaded spring, this brings the shackle to the right position when the weight of the trailer is set on it. i've seen too many with them forward, and the spring dog locked up over the mount when they we're overloaded.

[tigger1]

My vote is for the shackle to point to the rear a little bit for the reason previously stated.

[alanh]

I think it depends on the arch of the spring. A spring that has a very high arch will increase in length much more when overloaded than a spring that has very little arch will. The shackle on the high arch spring will need to be located farther back to help compensate for the increase in length as the spring is compressed. When the spring is flattened out (max. length) from being overloaded, I wouldn't want the shackle to be more than 45 degree angle to the rear.

[moe1942]

Persoally I would use a torflex axle but since you already have the springs that isn't an option. The spring in your picture shows the link in almost the right position. move it back a bit so the link is at a 45 degree angle, Visualize what the spring does when under load. It gets longer. therefore you want the link to move back and forth but not back so much that it will go overcenter.

All this is done in an unloaded condition. As already pointed out, go to a trailer sales with tape measure and hope they have placed their springs in the right location. Hard to explain how to do this...

[charlez]

Ok, everybody, thanks for the info. After looking at it with your input, here's how I see it.

When the spring is loaded, it will flatten out and get longer. The rear eye, will move further back.

If the rear mount is slightly forward, the shackle is already pointing backwards and will continue to go backwards as the spring lengthens. (Good)

If I were to put it so the rear mount is back slightly (shackles pointing foward), then as the spring lengthens, as the shackle goes straight up and the whole thing has to jump over-center to keep going.


I also see that you would not want it too far forward or it will bottom out under heavy load and bind up.

I think I will be mounting them slightly forward.

[DavidLH]

I had some literature once from a manufacturer but can't find it :-(. It said to mount the rear hanger one inch behind the spring eye. I have used that method on about 2 dozen trailers and have never had any problems.