Building a trailer....

[kevbooth]

I'm putting together a trailer for my buddies airboat, and I have a question or two about tandem axles.

I need to know how far apart to set the spring hangers. I've done a couple of single axels before, but the tandem has me stumped. Eye-to-eye on the springs is 25 3/16", and eye-to-eye on the tandem coupler is 5 3/4".

Also is it "better" to have the springs set over the axle, or under? I guess the better question would be what are pro's and con's of either?

Thanks in advance for any help on this one. I know there are a couple of trailer guys on here, and some of the previous posts have helped a ton already on this project.

Later,
Kev

[aametalmaster]

The big difference of over or under slung is the trailer height. Over slung will be higher with a small fender and under slung will be lower with a tall fender. Just put the side shakles for the rocker about a 60 degree angle. I will find you a picture..Bob

Look here: http://www.abctrailerparts.com

[dabar39]

You need to find the center point of where you will be placing the axle and mount your equalizer hanger there, then simply measure 30 1/2" forward for your front spring hanger and 30 1/2" rearward for the rear hanger.

Axle placement is generally suggested at the 60% rearward position for a 15% tongue weight, but the center of gravity will be different with the motor on an airboat hanging behind the axles, you may have to play around a bit to find your preferred location to ride correctly. If you have a problem getting the proper axle location let me know and I'll tell you how to do it with a bath scale.

As Bob has already stated the only real difference in the springs being over or under the axle is about 4 1/2" height difference. In your case I would think you would be better off with the axle above to keep the trailer lower for easier loading and unloading. Dave

[kevbooth]

Thanks guys!

Later,
Kev