Slightly OT: How to test trailer leaf springs

[DerbyDad03]

Is there a way for me to test the leaf springs on this trailer? You know, something like the old "shock test" on cars - step on the bumper. any more than 1.5 bounces and you needed shocks.

It seems to bounce more than it used to, both loaded and almost empty. Maybe it's just me, but things that used to stay put inside the trailer seem to get jostled around more than in the past. The handling doesn't seem to have changed, like I don't see it bouncing back around behind me. I followed it a few weeks ago and it seemed fine on both highways ansd side roads.

For example, the spare tire is held against the side wall with a piece of 2 x 4 bolted to a upright shelf support and pressed against the rim. Been that way for years. Yesterday I opened the trailer after a

60 mile ride and found it lying in the middle of the trailer. It's things like that that make me think it's bouncing more than it used too.

Tire pressure is fine.

Thoughts?

[DerbyDad03]

Yeah, saw those videos. That's why I worded my question the way I did:

"Is there a way for *me* to test the leaf springs on this trailer?" ;-)

I'll check the alignment clamps. If any are missing I'll throw some tie-wraps around the leafs. ;-)

[dennisgauge]

No, there is no test.

Are the springs sagging more than usual under load? Are they bent/broken?

Did you change tow vehicles to something with a stiffer suspension?

Your tire moving may be a red herring. It was held in with a 2x4 which pres= umably was untouched for years. The board got polished by the constant rubb= ing of the tire against it, and probably shrunk a little due to moisture lo= ss. Whoop, there goes the tire...

[Larry W]

Assuming it has leaf springs like most trailers do, it is possible that broken or sagging springs are allowing the suspension to bottom out, resulting in increased shock to trailer and contents. Examine the springs for cracks, broken or missing leaves, shackles, etc. and take a look at the distance between the bump stop and whatever it hits. Can't give a spec for that, but it should be a "reasonable" amount, say a few inches at least.

[Ashton Crusher]

Sounds to me like you need new shocks.

[DerbyDad03]

Excellent question. If I could go back a few years and look at the springs = under load to establish a baseline, I could probably answer that. ;-)

However, not having worried about it before, I don't know what sag would be= considered "usual" so I don't know if they are sagging "more than" that.

Not as far as I can tell.

No.

esumably was untouched for years. The board got polished by the constant ru= bbing of the tire against it, and probably shrunk a little due to moisture = loss. Whoop, there goes the tire...

If it was just the tire, I'd agree, but as I said in my post "For example..= ." That was just one example.

Anyway, the inspection is up in a few months. When it's due, I'll take it t= o a trailer shop and see what they can tell me.

[Bill]

Right. I bought a used trailer with no shocks - stuff would fly all over the place when hitting a bump in the road.

[Jules Richardson]

I could imagine excessive vibration - rather than bouncing - causing all sorts of problems, too. Maybe transmitted via the trailer hitch from the tow vehicle, or due to a bad wheel bearing, or due to an out of balance wheel etc.

cheers

Jules

[willshak]

DerbyDad03 wrote the following on 8/20/2012 2:41 PM (ET):

How old are the shocks? how much do you use the trailer? They do wear out. I'd replace them

[jamesgangnc]

something like the old "shock test" on cars - step on the bumper. any more= than 1.5 bounces and you needed shocks.

It seems to bounce mo= re than it used to, both loaded and almost empty. Maybe it's just me, but t= hings that used to stay put inside the trailer seem to get jostled around m= ore than in the past. The handling doesn't seem to have changed, like I don= 't see it bouncing back around behind me. I followed it a few weeks ago and= it seemed fine on both highways ansd side roads. For example, the spare ti= re is held against the side wall with a piece of 2 x 4 bolted to a upright = shelf support and pressed against the rim. Been that way for years. Yesterd= ay I opened the trailer after a 60 mile ride and found it lying in the midd= le of the trailer. It's things like that that make me think it's bouncing m= ore than it used too. Tire pressure is fine. Thoughts?

If it is old and has multiple leafs then my guess would be that they have r= usted together and the "bounce" you now have is from the tires absorbing th= e impacts more than the springs. This is pretty common with old trailers t= hat have multiple leafs. They sit too long and then the leafs rust togethe= r. My boat trailer has this problem. I think there are new thick single l= eaf composite springs to counter this but they ain't cheap.

[dennisgauge]

s under load to establish a baseline, I could probably answer that. ;-)

be considered "usual" so I don't know if they are sagging "more than" that.

Unfortunately, that was your one and only chance at being able to diagnose = the problem without resorting to the parts shotgun. Now all you can do is c= hange parts until you figure out what the problem is.

presumably was untouched for years. The board got polished by the constant = rubbing of the tire against it, and probably shrunk a little due to moistur= e loss. Whoop, there goes the tire...

..." That was just one example.

It was a poor example, because as I clearly showed it could be explained by= other circumstances.

to a trailer shop and see what they can tell me.

They will either be honest and tell you there is no test, or they will be d= ishonest and end up selling you a new set of springs that you may or may no= t need.

[DerbyDad03]

It can't need "new" shocks since it never had shock to begin with, only leaf springs.

Since stuff didn't "fly all over the place" up until recently (as far as I know) it can't a need for "new" shocks.

[DerbyDad03]

This trailer does not have shocks, only leaf springs.

[DerbyDad03]

Trailer doesn't have shocks, only leaf springs.

[DerbyDad03]

ngs under load to establish a baseline, I could probably answer that. ;-)

d be considered "usual" so I don't know if they are sagging "more than" tha= t.

e the problem without resorting to the parts shotgun. Now all you can do is= change parts until you figure out what the problem is.

True dat...

h presumably was untouched for years. The board got polished by the constan= t rubbing of the tire against it, and probably shrunk a little due to moist= ure loss. Whoop, there goes the tire...

le..." That was just one example.

by other circumstances.

Had I said "The covers popped off 3 storage totes" or "My tool box rotated 90 degrees" or "2 storage totes fell over" I'm sure you could have explained all of them away also. I doubt there is a perfect example that I could have given.

it to a trailer shop and see what they can tell me.

dishonest and end up selling you a new set of springs that you may or may = not need.

I've never known them to be dishonest in the past. Let's hope they don't start now.

[Atila Iskander]

WE need to find out what kind of springs you have Start here

[DerbyDad03]

It'll have to wait until this weekend. The trailer is not at my house and I won't be where it is until Friday.

I'll compare what I have to the pics on the website as soon as I can.

How will knowing what types of springs I have help diagnose the problem?

[Vic Smith]

What problem?

[Atila Iskander]

If memory serves, the diagram will tell you if any parts are loose or worn It appears that with leaf springs as shown, the damping usually provided by a shock absorber, comes for the springs sliding against each other If the springs are loose, then there is little damping and the trailer should keep bouncing up and down If the springs are too tight, then there is no "give", and the trailers is "stiff-legged"

[micky]

Trailers that size don' thave shocks. Don't worry about it until you have trouble.