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RangerJay · 09-04-2012, 12:18 PM

Looks like the shocks on our 02 Bambi need to be changed.

I seem to remember reading somewhere that an Airstream should only have Airstream shocks - so I asked the question and was told that what I had remembered was correct - an Airstream should only have Airstream shocks.

They aren't terribly expensive - so that was a very pleasant surprise - and are on order now.

But I'm curious.

I see that others on this forum have used different shocks - presumably without consequence. Is there really a difference?

Thanks,

Jay

Belegedhel · 09-04-2012, 08:41 PM

I believe the important attribute of these shocks is that they are designed to be mounted in a near horizontal position. Question I have is, how did you decide that yours were worn out?

purman · 09-04-2012, 08:56 PM

Quote:

Originally Posted by Belegedhel

I believe the important attribute of these shocks is that they are designed to be mounted in a near horizontal position. Question I have is, how did you decide that yours were worn out?

In general shocks last 60,000 miles or less. As far as time goes I'm not sure. But like everything else it can't last forever.

Phoenix · 09-04-2012, 10:42 PM

Testing shocks is kind of a no-brainer. Remove the mounting bolt at one end and push and pull on the end of the shock. If you get no (or very little) resistance, the shock is bad. Also, the shock body often is wet or very dirty where oil has leaked from the shaft, also an indication that it needs replacement.

L911 · 09-04-2012, 10:53 PM

I wonder how "coil over" shocks would work on an AS? I had a pair on my Shasta, it helped with axle droop. Just curious.

Phoenix · 09-04-2012, 11:01 PM

Since the shocks are mounted horizontal to the ground on Airstreams, I'm not sure the coil-over shocks would do any good. Just a guess...

Also, the shock mounting points are not super-strong. They appear to only be for shock dampening and probably wouldn't hold up very well to any heavy stresses.

slowmover · 09-05-2012, 03:49 AM

"Testing" via compression is addressed by Andy/Inland RV in another fairly recent thread on this same subject. More about speed than "felt" resistance (in how compression is checked). Do a search.

As this is not a vertical mount shock absorber trying to control a steel spring I think that staying with the standard offer is likely the easy & best choice.

Ahab · 09-05-2012, 08:05 AM

Quote:

Originally Posted by purman

In general shocks last 60,000 miles or less. As far as time goes I'm not sure. But like everything else it can't last forever.

This was true 20 or 30 years ago. Today they can easily go 100,000.

Inland RV Center, In · 09-05-2012, 09:45 AM

Quote:

Originally Posted by L911

I wonder how "coil over" shocks would work on an AS? I had a pair on my Shasta, it helped with axle droop. Just curious.

They will cause the shock "studs" to break.

The studs are not designed to lift weight.

Andy

RangerJay · 09-05-2012, 05:18 PM

Quote:

Originally Posted by Belegedhel

I believe the important attribute of these shocks is that they are designed to be mounted in a near horizontal position. Question I have is, how did you decide that yours were worn out?

First - thanks to everyone for their replies.

To Belegedhel's question - there was fairly sudden tire wear on the curbside tire - heavy wear on the inside of that tire - almost bald - and some cupping? (not sure of the proper term) on the interior treads. All this happened this season. It probably should be noted that the running gear was serviced this spring and no tire problems were noted at the time - we have not put a lot of miles on the trailer this year (about 2,000 KM) - we did return from a long trip to Alaska last year (both tires looked great at the end of the trip) - total mileage on these tires (Goodyear Marathons) is about 50,000 KM - roadside tire still looks great (very even wear across the tread - lots of tread left) - air pressure when travelling is checked every day - tire and bearing temperature is also checked every day and the curbside tire typically runs slightly warmer than the roadside tire but both are always cooler than the truck tires.

The dealership examined the axle, alignment, shocks and bearings - the only issue they found was that the shock on the curbside of the trailer was sticking - they weren't sure this would cause the problem of the tire wear - but because this was the only problem they found it was me that insisted the shocks be changed. They were going to change the shocks with an automotive substitute - it was me that insisted it be an Airstream shock.

Hope this answers your question.

Jay

Phoenix · 09-05-2012, 08:40 PM

Though I'm sure it's possible, I have never seen a "sticking" shock. Did they demonstrate this failure to you? Regardless, shocks are relatively inexpensive; and changing them (if in doubt) is not a big thing, especially if you do the labor yourself.

Regarding the irregular wear on the Goodyear Marathon, I'd have the wheel and tire removed so you can inspect them thoroughly. I suspect that you'll find that the belts have slipped/shifted, and the tread is starting to separate. If the tire looks OK, except for the irregular wear, almost bald tread and cupping (conditions which don't sound good to me), I'd have them balance the wheel and tire. I'll bet it is seriously out of balance, and probably out of round, too (i.e., not "true"). Plus, you'll probably see the tread squirming around when the tire is slowly spun on the balancer.

If the wheel alignment, bearings, brake drums/shoes, etc. are OK, all that's left to consider is the tire(s). Just my opinion, but it may be time to seriously consider switching to 16-inch wheels and LT tires.

purman · 09-05-2012, 08:46 PM

Quote:

Originally Posted by Ahab

This was true 20 or 30 years ago. Today they can easily go 100,000.

Man, I drive on dirt roads to much.

Belegedhel · 09-07-2012, 09:54 AM

When I asked how it was determined that the shocks were worn out, I was just wondering if there was more to the story, and it sounds like there is a lot more. I have read several threads and heard many discussions regarding the shocks, and have reached the conclusion that they might be deemed a "belt and suspenders" sort of affair. The actual travel of the shocks is very small because of the horizonal positioning, which causes several owners to question whether they really do much at all. I have heard of people going shock-less and not having any negative report.

At any rate, I would agree that replacing the shocks is a cheap and easy thing to do (assuming you don't have to drop the axle to do it, which is what I would have had to do with the original axle on my '73). I am suspicious though, that the problems you describe have some other cause.

As to the "Airstream" specificity of shocks, as I mentioned above, I have heard that one must use a shock designed for horizontal mounting. Many of the modern automotive shocks advertise being gas filled, etc., which makes me wonder whether it makes any difference how they are positioned.

Belegedhel · 09-07-2012, 10:05 AM

RangerJay--just reread your detailed explanation above and had a follow-up question.

I can imagine that if your shock stuck hard so that essentially the suspension on that side of your trailer could no longer travel up and down, everytime the street side suspension compressed, the trailer would lean, and you would wear the inside of the curb side wheel. But knowing also that the shock mounts aren't really designed to take that kind of abuse, I wonder if any deformation was observed in the shock mounts, or any other damage that could be attributed to driving on non-moving suspension has been noticed.

**Action** · 09-07-2012, 02:37 PM

Shock absorbers dampen or restrict movement of the axle in relation to the body of the vehicle. (They do not change ride height of the vehicle) Shocks do this with fluid that is pushed internally through orfices and they rely on gravity to do this job.

With this you will know that a bad shock is one that displays ....
1) Zero movement - it is frozen (rusted) in position
2) Unrestricted movement- internally the fluid is no longer being pushed through a restricted opening
3) There is a shock fluid leak externally - seal leak will eventually cause much of the fluid to leave the shock
4) Other mechanical damage such as broken ends or stripped off nuts or fasteners

The shock can also become weak and yet not completely unrestrictive in the dampening action. Internal seals starting to fail or other causes. Good news is the design of the torsion axle provides some measure of dampening axle action, so shock absorbers are not used as hard as they are in non-torsion axle applications. Other things that will contribute to longer service life are -

Tires and wheels that are in good condition
Tires and wheels that are in balance for up and down movement
Torsion axles that are in good condition and the internal rubber rods are not hardened up.

In 1967 Airstream switched from a mostly vertical mounted shock absorber to a mostly horizontal mounted shock absorber to create more space internally in the coach. This also required a design change internally to the shock because gravity was not pulling the dampening fluid in the same direction as a vertical mounted shock. Very few to no other applications are like this so the after market parts industry has not created a replacement because sales volume would be so low. (Supply & demand) Hense when replacements are needed an Airstream dealer is the source.

The mounts for Airstream shock absorbers are not as beefy as other vehicle applications. They won't accept the added pressure from coil over springs or gas shocks or any other design that increases the pressure on the mountings. Any added pressure will cause the shock mounts to deform or break off.

I hope this helps

>>>>>>>>>Action

Inland RV Center, In · 09-08-2012, 08:49 AM

Quote:

Originally Posted by Belegedhel

RangerJay--just reread your detailed explanation above and had a follow-up question.

I can imagine that if your shock stuck hard so that essentially the suspension on that side of your trailer could no longer travel up and down, everytime the street side suspension compressed, the trailer would lean, and you would wear the inside of the curb side wheel. But knowing also that the shock mounts aren't really designed to take that kind of abuse, I wonder if any deformation was observed in the shock mounts, or any other damage that could be attributed to driving on non-moving suspension has been noticed.

Why switch to a "maybe", instead of using a "for sure"?

Airstream horizontal shocks, are very reasonable.

Andy

JamuJoe · 09-09-2012, 08:31 AM

Action - Not to split hairs, but I would say that it is FORCE, not gravity, that pushes the fluid in a hydraulic shock absorber through orfices to dampen movement. Gravity is of course a particular force that attracts a body toward the center of the earth. A hydraulic shock absorber does not have to be vertical to dampen movement. You likely have a horizontal shock absorber on your car or truck - it's called a steering stabilizer. Monroe makes them and describes them as horizontal shock absorbers.

**Action** · 09-10-2012, 08:40 AM

Gravity keeps the fluid in the correct position of the static shock orfice. (At rest) If the shock is mounted in a different than design position (A verticle designed shock mounted horizontally) then the fluid settles in a different area because of gravity into a position that renders the shock ineffective.

A verticle designed shock will not be effective on a horizontally designed system such as post '66 Airstreams.

>>>>>>Action

JamuJoe · 09-10-2012, 10:11 AM

Action, I stand corrected. A bit more research revealed the variations in shock design, though not much detail on horizontal shocks. According to Monroe, "A conventional two-tube shock absorber must be mounted somewhat vertically". "Somewhat" is pretty vague.

Thanks for the explanations.

**Action** · 09-10-2012, 02:30 PM

Quote:

Originally Posted by JamuJoe

"A conventional two-tube shock absorber must be mounted somewhat vertically". "Somewhat" is pretty vague.

Thanks for the explanations.

Yeah I am not sure there is an exact spec on how far past vertical one can go before there is an issue. In my experience I would think most vertical shocks are good to about 10 to 15 degrees. Could be more than that and I am just not clear before it is an issue.

Way back before the internet, I mounted some regular shocks up side down on a older Ford Galaxie 500. The correct ones were not available because there was not a high demand and limited model application. (I installed a front shock on the back because it "fit") I discovered from a life experience that shocks have to be mounted in a more or less correct designed position in order for them to do the job. Other wose I am just mounting more useless baggage.

>>>>>>>>>Action