Why do you need shocks?

[dznf0g]

Cheap oil filled shocks are pretty well done at about 50k. In addition to the failure modes mentioned above, the internal valves and seals wear out.....without external oil leakage many times.

USUALLY, us low mileage ASers will see leakage before they wear out. I had 2 of my originals leaking when I got my Classic...but it had sat for most of 4 years and I'd bet the shafts were pitted from lack of use and oil "wiping".

Note: when testing these particular ones, they do not have much resistance upon compression, but have quite a bit on extension. This is normal for these models. Test only in an upright position to avoid sucking air into the valve chambers.

[boondockdad]

Been searching the "shocks" topic for a bit, and the one thing I haven't seen anyone mention is tire damage from worn shocks.

I'm getting some pretty severe 'feathering' and 'notching'- chunks of tread missing. Some Google-Fu tells me this can happen when bad shocks don't keep the tire on the pavement, and the constant bouncing will literally take chunks out of the tread.

Is this an occurrence with cars/trucks (where I read the info) only? Or has anybody else seen this on their Airstream?

[Ray Eklund]

My 2006 Airstream Safari 23 footer was taken to Jackson Center, OH with a list of warranty items that needed, or requested, to be fixed, repaired or replaced. This was in 2008.

Among the list of the above was a leaky shock absorber on the right side of the trailer.

The crew could see that the shock absorber had a leak, as dust would adhere to it. The shock was NOT replaced.

They "are pretty much non functional and for looks".

I never gave it a second thought until after reading this Thread.

I never had any issues with what the shocks did for the trailer, if anything, but after eight years the tire wear was normal and trusted that the mechanics at Jackson Center had an opinion or from experience, that what they told me was correct.

(The current owner of my former 23 foot Safari lives in Colorado and maybe notice this Thread and can look at the shock and comment as to anything new to add.)

[boondockdad]

Originally Posted by Ray Eklund

"pretty much non functional and for looks"

Hmm. Describes my youth.

But, seriously.


And I was hoping this would be an easy fix...

[slowmover]

Wheel balance is first thought. Assembly balance, really. Wheel/ tire plus drum, etc as a single rotating mass.

[dwightdi]

Shocks dissipate the energy generated by hitting a bump. Airstream shocks are pretty horizontal and can be tested that way. Shocks operate much the same way frictional dampeners work for sway. They dampen the tendency for wheel hop. They are a good thing, but add expense that cheap trailer manufacturers do not want to pass on to their customers.

[OTRA15]

What kind of tires do you have and what is their age, date of mfg., and mileage on them?

I would doubt that your trailer tires ever leave the pavement while traveling at highway speeds.

During a brief moment of transitioning over small bumps, curbs, rocks etc., a tire may briefly have air under it, but nothing to cause any tire damage IMO.

Yes, trucks and cars with 2 front tires and 2 rear tires might experience some kind of tire damage from severe bouncing, but unlikely, again IMO.

Defective tires seems like the most likely cause. Are all 4 tires having the same problem?

Originally Posted by boondockdad

Been searching the "shocks" topic for a bit, and the one thing I haven't seen anyone mention is tire damage from worn shocks.

I'm getting some pretty severe 'feathering' and 'notching'- chunks of tread missing. Some Google-Fu tells me this can happen when bad shocks don't keep the tire on the pavement, and the constant bouncing will literally take chunks out of the tread.

Is this an occurrence with cars/trucks (where I read the info) only? Or has anybody else seen this on their Airstream?

[Action]

Originally Posted by OTRA15

I would doubt that your trailer tires ever leave the pavement while traveling at highway speeds.

During a brief moment of transitioning over small bumps, curbs, rocks etc., a tire may briefly have air under it, but nothing to cause any tire damage IMO.

The tires don't have to leave the ground with air under them for a tire to loose control or grip on the road surface. All they have to do is unload enough in a moment that the tire looses grip and then full force comes back down.

The job of a shock is to restrict that movement and the restriction only has to be momentarily as a new force will come in the next moment.

>>>>>>>>>>Action

[OTRA15]

Fair enough, but the OP seemed to think that tires leaving the ground and slamming back down were the cause of his tire issues, with which I disagree. [edit -- OP: "bad shocks don't keep tire on pavement . . . constant bouncing . . . "]

My wording was not great, but the real cause of the damage is not from bad shocks IMO.

Curious to know your best guess about his tire damage . . .

Originally Posted by Action

The tires don't have to leave the ground with air under them for a tire to loose control or grip on the road surface. All they have to do is unload enough in a moment that the tire looses grip and then full force comes back down.

The job of a shock is to restrict that movement and the restriction only has to be momentarily as a new force will come in the next moment.

>>>>>>>>>>Action

[Ray Eklund]

Try either the south or north routes into and out of Chaco Canyon.

If you are lucky enough to have THREE tow vehicle tires on the ground at one time and at least TWO tires of the Airstream on terra firma... while traveling sideways, it is a great test for those 'bicycle shocks' on an Airstream.

Also it helps if you have a mouth guard to prevent any permanent damage to your teeth... in the process that seems to be never ending.

[Action]

My point is the OP did not use the words "leaving the ground."

The statement made was, "when bad shocks don't keep the tire on the pavement" The tires do not have to leave the pavement to keep the tires in CONTACT with the pavement. That may be splitting hairs however any time the tire is not in contact with the pavement there is loss of control. When the tire regains control it is usually done in a very forceful way. Under speed that force repeatedly can do damage to a tire.

The same can be said for a slow speed maneuver when a multi axle trailer is taking a sharp turn. The tire(s) that slides is not in total contact with the pavement.

As to the possible causes of this poster's issue, I believe it may be some or all of the items posted above. IMO
Assembly Balance
Weak shocks - The unit is 8 years old
And I would add improper inflation and/or tires that are not correct for the load.

>>>>>>>>>>>Action

[boondockdad]

Here's some better lighting.


These are E-load Michelin LTX, inflated to 75psi. Wheels are balanced, and Centramtics. Installed 4/11/2012, have almost exactly 24,000 miles on them. Action's right, the shocks are original. Took possession 10/2007. 54,550 miles on trailer, to date.

Always CAT, and Sherline, so I know it's not an overload issue.

Was calling around this morning to try and have a shop true/shave them up before I replace the shocks. I guess that's a specialty most franchises don't offer. But, even if I can't get them trued, I won't be replacing them.

At this point, if I assume the shocks are bad, the only other thing that needs checking is alignment.

I'm surprised nobody else has ever seen this on a trailer...

[Action]

If you balance & rotate the tires that wear pattern will be interrupted, after the issue is addressed.

One of the neat things about rubber torsion spring axles is the amount of "wheel hop" that is induced. Or lack of wheel hop. This spring type tends to "hop" less than metal springs. However when large amounts of load are applied to any suspension system at fast speeds the negative issues are magnified. Shocks will only dampen the movement. To eliminate of some of the movement is addressed with balancing tire/wheel/hub assemblies. Centramatics will pick up the difference as the tire wears or if the hub was not balanced. My understanding is they will not correct gross out of balance conditions. However I have very little experience with the product. The whole suspension system works as a unit. Some times it is one component and other times is more than one in less than good condition.

BTW over inflation can be almost as bad as under inflation. (Not saying that is YOUR issue) Knowing the towed load and proper inflation for that load is the ideal.

>>>>>>>>>Action

[OTRA15]

Originally Posted by boondockdad

. . .
I'm surprised nobody else has ever seen this on a trailer...

Thanks, a much better image. Is this uniform on all four tires?

Is it possible that one (or more) wheel drums are not up to par, and cause the brakes to grab every so often (on a microscopic level) thereby causing the irregular tire wear?

Have you inspected all four wheel drums and brakes recently, for unusual wear or appearance?

Is your tire dealer nearby, or any Michelin dealer for that matter, and have you received any feedback from this arena?

[OTRA15]

Originally Posted by Action

My point is the OP did not use the words "leaving the ground."

The statement made was, "when bad shocks don't keep the tire on the pavement"
. . .
That may be splitting hairs
. . .

Ya think?

Originally Posted by OTRA15

. . .
My wording was not great, but the real cause of the damage is not from bad shocks IMO.
. . .

Replace the old original shocks to start IMO.

[r carl]

Originally Posted by boondockdad

Here's some better lighting.


These are E-load Michelin LTX, inflated to 75psi. Wheels are balanced, and Centramtics. Installed 4/11/2012, have almost exactly 24,000 miles on them. Action's right, the shocks are original. Took possession 10/2007. 54,550 miles on trailer, to date.

Always CAT, and Sherline, so I know it's not an overload issue.

Was calling around this morning to try and have a shop true/shave them up before I replace the shocks. I guess that's a specialty most franchises don't offer. But, even if I can't get them trued, I won't be replacing them.

At this point, if I assume the shocks are bad, the only other thing that needs checking is alignment.

I'm surprised nobody else has ever seen this on a trailer...

Were all tires wearing like this one? Any update?

[boondockdad]

Yep, all four tires and they all had pretty much the same "wear".

Note: my previous GYM, and Maxxis' never wore like this. They exploded and caused massive headaches and $20,000 worth of damage, but they never wore funny.

So, here's the dates and odometer readings:

04/11/2014 30,650 Michelin LTX M/S 22575R16 and Sendel T02 balanced and installed.
04/11/2016 53,400 Installed Centramatics.
08/11/2016 54,789 Same side rotated tires.
04/17/2017 56,565

It's raining pretty good right now, so I'll post a pic later. Hard to say if the tread is wearing evenly, now. I'll let you be the judge.

[boondockdad]

Here they are

[carl2591]

at first glance it appears to be misaligned axles.. have they been check just to make sure that is not part of the issue. the wear does look odd for sure.

be interesting to find out what the issue is for tire to wear like that.

Originally Posted by boondockdad

Yep, all four tires and they all had pretty much the same "wear".

Note: my previous GYM, and Maxxis' never wore like this. They exploded and caused massive headaches and $20,000 worth of damage, but they never wore funny.

So, here's the dates and odometer readings:

04/11/2014 30,650 Michelin LTX M/S 22575R16 and Sendel T02 balanced and installed.
04/11/2016 53,400 Installed Centramatics.
08/11/2016 54,789 Same side rotated tires.
04/17/2017 56,565

It's raining pretty good right now, so I'll post a pic later. Hard to say if the tread is wearing evenly, now. I'll let you be the judge.