Do I have to many leaf springs?

[andreuther]

I am clueless when it comes to suspension and have no idea if this is to much for my TD. So I have 4 leaf springs on the each side of the old trailer I purchased. Measuring horizontally end to end they are 31'', 29'', 25'', and 21.5''. Each leaf is about .25'' thick and 1.75'' wide.The trailer also has full sized tires. Any input would be appreciated!

[Corwin C]

Unfortunately there isn't a definitive answer to your question. There are literally thousands of spring/axle configurations and it is just a guess as to what the capability of your axle and springs are. I use many different trailers. I have a 2,000# capacity utility trailer that has three leaves and often use a 50,000# capacity equipment hauler that has large single leaves, so the number of leaves isn't a good measure. Size and length are not the best way of determining capacity either. If there are manufacturer markings on the axle/springs, that would be your best bet to determining exactly what you have.

My suggestion ... the trailer you got the parts from was most likely properly designed for the loads that it was intended to haul. If you are close to that loading, it is probably a good match. Off the cuff I would say that you are probably OK. Also, remember that too much capacity is better than not enough. If you have too much capacity, the ride will be rough. If you don't have enough, there's the possibility of catastrophic failure.

[andreuther]

Thanks for the reply! Is there a way to test for the correct amount of spring back that the trailer should have?

[michaelrsydney]

As Corwin says, it all hinges around the weight of the finished trailer. You will not know until you have the TD finished and loaded for a trip. Over stiff springs are not a great idea as the constant bounce is stressful for the driver and damaging to the tow car, trailer and contents.

This web page gives a useful chart of one company"s spring range and capacities, but there could be many variable with other manufacturers. I would suggest weighing the Barndrop and then checking a local supplier for a similar specs chart. Springs are cheap and easy to change.

http://www.alko.com.au/vehicle-technolo ... e-springs/

[aggie79]

I agree with all of the above.

One shade tree method is to do a bounce test. With the Barndrop loaded with the normal amount of camping gear, and hitched to your tow vehicle, either stand in a doorway or preferably open the hatch and stand on the galley floor and try to bounce up and down. Another method is to tow your Barndrop down a bumpy road and have someone observe if it is bouncing all around or dampening the bumps.

If you little to no suspension movement, your springs have too high of a load rating for your use. Lowering the tire pressure will help smooth the ride somewhat. I run my teardrop tires at 25 psi.

[KCStudly]

I'm wondering about the fact that you do not appear to have any perches between your springs and axle. I have no prior experience with square axles (which, BTW, I had not realized in the other thread where we were "talking" about how it was extended). Normally there is a perch with a hole in it that receives the spring bolt/locating button. Are there holes drilled into your outer sleeve to receive the spring bolt?

There's a good thread here somewhere that shares details on how to rebuild and grease a spring pack. Doing this could improve the performance of a stiff pack w/o resorting to removing leaves.

Here's the link.

[andreuther]

That link about rebuilding the leaf springs and axle was perfect. I think I will test it as is and then do the rebuild to see the difference. I just checked and it seems that one set of leafs is bolted together and the other is not, easy fix. Thanks for all the help!

[Kody]

What they all said is good info. With a spring at the length you stated, it should be ok as is. If it is found to be hard riding, remove the lowest spring leaf and try it out over some bumps or rough road. The most important thing is to have the shackle (shown on the left in the photo) correctly positioned. When the finished T/D is sitting on the ground and the tow bar level, the lower pin of the shackle must be 3/4" to the rear behind the top pin. By having the shackle at this angle, the spring will deflect without jambing. If the shackle does not swing backwards, the spring can and most times, will break and the ride will be very rough.
It will also help greatly by chamfering the top edge of the spring leaf on the ends. This helps the leaf to slide under/along the leaf above it. As the post on repairing springs shows, clean and grease the surfaces of the leaves. Some people claim that the uncleaned (and rusted) surface adds friction to the leaves and stops all the bounce. I much prefer to have the leaves flexing and sliding unimpeded. The spring has its own dampening quality and it will quickly slow down and stop. This is where a shockie can be a huge help to stabilize the T/D if the bouncing is excessive.
Good luck with your springs,

Kody

[georgiadawg]

aggie79 has it right.

You can't just look at the weight numbers, it depends on how it's balanced. I have a boat trailer that used to bounce up a foot in the air whenever I went over nearby train tracks. Everything was weighted just fine, but I wasn't centered over the axle. I readjusted how the boat sat on the trailer, putting a little more weight on the axle and off the tongue, no more bouncing over the train tracks.

As aggie79 said, sometimes you just have to drive down a bumpy road to see how it bounces.