Shock Absorbers

[jfowler218]

Is there an average lifetime ( miles or age)for A/S shocks. Is it best to replace them periodically or just wait for signs of leakage?

[2airishuman]

since the role of these shocks is QUESTIONABLE at best ...

replacement is only necessary after leaks/mechanical failures/trauma ...

or when replacing ancient axles that have settled significantly...

or maybe when uprating axles with a DIFFERENT angle.

given the newness/age of your stream the shocks should be fine for decades.

cheers
2air'

[Lance M]

Jfowler,
Actually the "Shock absorbers" dampen the spring. No damping means more springing. I'm not sure that you can tell from the tow vehicle by "feel" if or when the shocks are worn out. Definitely, if you see signs of leakage they should be replaced. You may notice uneven wear patches on the tire that are signs of a worn out shock.

[dznf0g]

Replace if leaking, for sure. Every few years, you might pull them off when repacking bearings or rotating tires and check them. Hold them vertically, with the shroud side up, and expand and compress them. You should feel resistance to your effort. If they move freely in and out, the internal valving and seals are worn.

My experience and "feel" for this is for automotive shocks, so I would need to try a new AS one off the shelf for a comparison feel for the "in use" units.

[2airishuman]

the op asked about 'lifespan' and IF regular replacement is needed.

rubber torsion axles are SELF dampening, especially when fresh.

the shocks are horizontally mounted, their movement characteristics are very different than tradition shocks.

neither dexter or henschens have ever indicated shocks were needed with their rubber axles...

in fact just the opposite is true, both companies have said "not required"...

many other trailers using a variety of torsion axles do so withOUT shocks.

an empty stream, IF it's gonna bounce or hop will do so regardless of shocks or not.

and in a fully loaded stream with properly spec'd rubber the dampening is inherent to the axle.

the forum is full of old threads that debate this issue, go read or call dexter.

this one post summarizes what many have reported...

http://www.airforums.com/forums/f155...tml#post552157

do these uniquely valved horizontal shocks provide some tiny/marginal value?

are there some 'oscillatory events' reduced by this belt/suspenders approach?

perhaps but there is very little independent/objective PROOF of that...

and much that sez just the opposite...

http://www.airforums.com/forums/f437...les-39688.html
________

again 4 the o.p.

regular shock replacement withOUT some clues to failure is not required or recommended.

cheers
2air'

[Lance M]

2Air,
Do you have shocks installed on your trailer? Or (traylah) as you so eloquently refer to it. If so, take them off and send them to the original poster.

[tkasten]

I installed a new henschen axle on my 65 Safari last spring. After several phone calls to Airstream Service Tecs. I was told I did not need the shocks. If fact, Airstream no longer uses them on 25' and under. Umm! All of the other manufactures do not use them with torsion axles. Something to do with the shock transfering some of the force into the axle. In any case the experts told me I didn't need them.....Tim - TAC MI 14

[Lance M]

Good to know. Thanks Tim.

[2airishuman]

indeed that brings up another aspect of the "are they necessary" issue,

a/s has been using rubber torsion for since 1962.

they've completely changed frame vendors and designs and specs several times in those 50 years...

they've changed flooring, C channels, ribs, and cladding significantly and multiple times.

they've gone from 2,000 lb units to nearly 6 tons and from narrow to wide bodies...

added tanks, used composites, tried slides and so on...

used 14 and 15 and 16 inch wheels from steel to heavy or light alloys.

and tires ranging from way old bias ply to radials, including ST and LT tires...

axles have been used with rating from under 3000 lbs to over 5,000 lbs,

with different starting angles, different brake designs, spindle sizes and so on.

in fact they've changed torsen axle designs 2-3 times and even manufacturers for the axles...

and how many changes or VERSIONS of horizontal shocks have been used with ALL of those changes ???

or how are the shocks different on triple axles or single axles across the production range ???

the o.p. doesn't need new shocks and there is no reason to remove them,

but the fact they are basically interchangeable only adds to the questions about function and necessity.

dealers, long time service techs, folks at the service center in j/c and so on...

regularly tell owners that the shocks are an 'appendix' like vestigial organ.

thanks for posting your 1st hand info tim,

that's basically and consistently the same thing noted in many of the threads on this topic.

cheers
2air'

[tkasten]

2air - well said.....Tim - TAC 14.

[Lance M]

2Air'
Thanks for the point to the threads above. Vernon seems to be the only guy to ever do any real testing with shocks. He did not post any data with or without shocks installed on his trailer with new axles. Still makes me wonder why an Airstream engineer would specify shocks for production if they are truly not needed.

[2airishuman]

it takes a HUGE about of effort for regular members,

to organize testing, gather data and post some results like vernon did...

hats OFF 2 all that are willing to add to the collective of real info here.

Originally Posted by pb379_2010

... Still makes me wonder why an Airstream engineer would specify shocks for production if they are truly not needed.

i agree this would be hard to sort out logically.

unfortunately, part of the package of info surrounding the "you need em" story sez a/s engineers are responsible for there use.

is that in fact HOW shocks came to be used?

i suspect something a lot simpler happened,

like wally tried a set on one of his mules and that tweak simply moved to the production line.

or perhaps a few units built for caravanning in the 3rd world demonstrated they value...

did some engineer type "test" this tweak? no doubt thats possible,

but it could simply have been to sort out install/fit and user issues...

is some engineering discovery at the root origin of why they were/are used? i doubt it.

it would be fun to find out how and why they really were added, then look at what if ANY REevaluation has been on going.

btw i'm keeping my appendix and tonsils as long as i can.



cheers
2air'

[slowmover]

Luckily, they're also cheap.

[Diesel1]

I lost my appendix 47 odd years ago, I've never noticed it gone. So in that vein I didn't weld on the shock brackets that Andy so kindly sent me with my new axles. A few thousand miles later I still can't tell their missing. Adios, John

[Diesel1]

Hey that last post was 444, thats International Harvester's engine designation for Ford's 7.3 Powerstroke. Kool huh? Adios, John