New Dexter Axle Problem, Any Hope?

[Frank's Trailer Works]

even though it has not happened yet, people sure get bent over these axles. Why is that? Is it because the cant in the main tube or is it that they just can't help themselves?

[overlander63]

Originally Posted by boatdoc

Hi overlande63; and 47WeeWind; Sarcastic questions and comments are not what Forums were intended for. Who cares, just do it. "Boatdoc"

No, "Boatdoc", it's when people start posting "popcorn" comments, the thread is usually about a micron from being closed or deleted. Sometimes people need to step back and take a deep breath before that happens.

[toastie]

Originally Posted by 3Ms75Argosy

Popcorn? Heck, I just finished my tub watching the last "what tow vehicle" thread! Axles, shocks, tow vehicles... just wait until someone mentions a bike rack on the rear!

Marc

I'm going to install a rear tire on the back of my 1955 Safari using a extra long trailer receiver weld to frame.........toastie

[silverleeper]

Originally Posted by toastie

I'm going to install a rear tire on the back of my 1955 Safari using a extra long trailer receiver weld to frame.........toastie

If you wish or need to post off topic there are several threads that you can do this in. Here are two examples. http://www.airforums.com/forums/f161...ead-60297.html and http://www.airforums.com/forums/f472...ing-24723.html.

[3Ms75Argosy]

Ok, me bad.. back to the subject at hand... what did you decide to do with your shocks? ANYTHING has to be better than the rigid old axle... are you keeping the shocks?
Marc

[87MH]

Originally Posted by 62overlander

... Is it because the cant in the main tube or is it that they just can't help themselves?

The boy jus' cain't he'p it.

[Dumpster]

Originally Posted by 3Ms75Argosy

Ok, me bad.. back to the subject at hand... what did you decide to do with your shocks? ANYTHING has to be better than the rigid old axle... are you keeping the shocks?
Marc

Sorry, I had moved from the eager student to the beer and popcorn crowd. I love controversy.

I haven't made up my mind yet entirely, although I am in no rush. I think having shocks is kind of cool, yet the jury appears out on their necessity. But since I sprang for the mounts, I think I will try an utilize them. I may take Boatdoc up on his very thoughtful and generous offer, assuming I can compensate him in some way.

I guess at the same time I was looking for a solution, I was hoping to bring this issue to the attention of the next person who does an axle swap. I have no experience with Axis' contruction, so don't know if the same problem exists there. But if I am reading Dexter's specs correctly, people shouldn't have this problem (or at least as pronounced) with #11 axles. At a minimum, requesting the shock mounts to be welded on the inside of the arm as opposed to the outside would certainly help. Again, that wouldn't go the whole nine yards in my case. A simple measurement of the original axle could tell you prior to ordering. One just needs to measure from the bracket to the base of the mount. This same measurement on my new axle will give me the difference I have.


Thanks to all who offered help and constructive feedback.

[Inland RV Center, In]

Originally Posted by Dumpster

Sorry, I had moved from the eager student to the beer and popcorn crowd. I love controversy.

Your Airstream requires "horizontal shocks". Your photo shows an after market red colored shock.

Please be advised that a vertical shock, placed in a horizontal position, is a waste of materials, since it will have as much effect on the trailer, as it would if you placed them inside one of the closets, in a basket.

If your going to use shocks, as you should, use the Airstream EXCLUSIVE horizontal shocks.

Andy

[Dumpster]

Your establishement sells the only approved shock for my trailer. But perhaps if we read the initial post, as our moderator suggested, we can avoid kicking the proverbial horse to death?

Originally Posted by Dumpster

Of obvious note is that the shocks are not AS “approved”. If I wind up having to ditch the shocks altogether, I will be glad I didn’t spring for new ones.

[Emerson75]

Dumpster,

Well just look what you started!

On a serious note...I have attached a photo of my Dexter axle install with new shocks installed. Granted you can't see the misalignment well from the the photo, but it at least shows a decent shot of the installed Dexter axles with new shocks mounted. Like I said before, just like yours, my shocks certainly run at a noticeable angle.

I understand you are trying to gauge what makes the most sense in your situation. In my situation I ordered new shocks before I even had the axles, because I knew the shocks were old just like the axles and after the expense of the axles the cost of the shocks seemed like a mute point. Granted I wish the placement of the shock mount was accurate, however I'm pretty satisfied with the results after I installed the new shocks, and found that the rubber bushings were pretty soft and seemed to absorb the misalignment better than I had expected after first glance. Overall I'm glad I opted to put shocks back on.

Good luck with your decisions. I'm very glad that my axle install is behind me! Now I'm in the process of replacing the rear belly pan and attempting to strengthen the frame to prevent additional rear end separation in the future. This whole AS thing (I've only owned one since the fall) makes me feel more like a mechanic than a camper!

Cheers,
Eric

[Jim & Susan]

Dumpster, I've been following your thread and have hesitated to jump in here, mostly because of the problems you've already encountered with an "axle thread". It really ticks me off when you try to obtain reasonable information in a thread and somebody jumps in and takes the thing in a completely pointless and useless direction. You have something of a unique problem here. Sad that the thread went so awry.

At any rate, I don't recall my shocks being so misaligned when we welded them on. I ordered the shock mounts loose (not welded) and a forum member, PizzaChop, welded them on for me. No problems at all. If you want, I can take a couple of pictures of the undercarriage as installed. But, it may be a couple days because of a completely saturated ground around the camper due to continual rains. Let me know if you want those pics. Look at my main thread here: http://www.airforums.com/forums/f226...nte-15132.html to see how I ordered and installed mine. Look to the end of the thread around Oct of last year.

BTW, you can order those shocks from any Airstream dealer. I bought mine from Out Of Doors Mart. A REALLY good group of folks to deal with: Out-of-Doors Mart MORE Airstream Parts on-line than anyone!!! And we accept PayPal. Ask for Dan. He's also a forum member here, but doesn't post all that much (hint).

Jim

P.S. I have a feeling I should know this, but who is John Galt?

[Jim & Susan]

Well, another forum member kindly reminded me that I did not order the shock brackets loose, as stated above, and he would be correct. At the time I ordered my axles, the brackets were not available for some reason that I can't remember now. We cut the brackets off the old axles and put them on the new.

I think it's late enough that I need to go to bed now.

Jim

[Dumpster]

Originally Posted by Jim & Susan

who is John Galt?

If you have ever read the book Atlas Shrugged by Ayn Rand (my own, personal 2nd bible), you would realize how fantastically classic your quote above is. It is also fitting (and for that reason, not off topic) that I feel like Atlas wanting to finally shrug off this thread. But I digress....

Thanks to you and Eric for the helpful posts. And no need to point me toward the Monte, as I have been following along with you; albiet silently. You should be very proud of what you have accomplished. I will take another look at your axle pictures. I have a hunch you wound up welding the brackets on the very inside of the arm? With that, I would still be curious if your brackets are perfectly aligned? I am not poking, I am genuinely curious about this for the next guy/gal.

Best Regards,
Dumpster

[putback]

From an off roader point of view traditional hydralic shocks in or near the horz position preform poorly and fail quickly. Gas shocks seem to work well. For moderate misalignment the "cheap" rubber bushings are very forgiveing. The "better" poly bushings are not, they can bend the thrust shaft and destroy the internal seals. An old hotroder trick for a shock that just can't been aligned. Find a friendly auto parts store and go through the cheap tie rod ends, ball joints, ect to find the specs you need, cut excess as needed and spot weld to the mounting plate. Ball/socket will releave stress of angle. 1st make sure there is clearance. Spotweld 'cause if you ever replace the shock odds are you'll have to cut the joint from the plate.

[Action]

Originally Posted by putback

From an off roader point of view traditional hydralic shocks in or near the horz position preform poorly and fail quickly. Gas shocks seem to work well.

You are correct in your statement about traditional shocks. However Air Stream horizontal shocks are not traditional shocks. Because of that, these horizontal shocks are only available at a Airstream dealership.

And gas shocks do not work in this application.

>>>>>>>>>>Action

[r carl]

Originally Posted by Inland RV Center, In

Torsion axles, when hitting a bump, tend to "chatter", sort of like a bouncing ball, because of the rubber rods.

Rubber bounces, we all know that.

The shocks, curtail {limit} that bouncing, since they are motion restricters.

Dexter can say whatever they wish, but they cannot over rule physics, or the behavior of rubber.

Andy

I agree with Andy, common sense tells me that shocks reduces sway, wander, and bounce for improved towing capacity. I would think that shocks reduce the surge caused by trailer motion feedback to the TV as when a semi passes you on an interstate. I dont want to tow a bouncing ball.

[barts]

If we consider what happens when a vehicle w/ a shock hits a bump, it is true that the force is somewhat higher on the initial reaction ... but the shock helps prevent the entire trailer from bouncing up and down several times after in reaction. Here's a graph on what various amounts of shock damping do to a step function input (which is like a bump in the road):



The interesting thing about shocks (ignoring gas shocks) is that the force they exert is proportional to the speed of their compression or extension.

Rubber torsion axles provide damping as well, intrinsically, because rubber has hysteresis: unlike steel springs, compression and expanding rubber absorbs significant amounts of energy (which is why tires get warm when driving):



Regular leaf springs do provide a little damping; the leaves rub together and create friction. This is actually counterproductive in terms of ride quality, and back when cars had leaf springs, placing greased cheesecloth between the leaves of the springs helped the car react more supplely to the road....

Whether or not a trailer w/ a rubber torsion axle needs shocks is an interesting question; I would imagine that depends a great deal on the characteristics of the rubber, number of axles, etc. If someone were to travel a section of rough road w/ an accelerometer-equipped trailer w/ and w/o shocks installed, much might be learned about the necessity of shock absorbers on Airstreams. Accelerometers used to hard to find outside a lab, but modern solid state versions are in IPhones, etc... there may be IPhone applications suitable for this already.

[TomW]

Originally Posted by barts

.. Here's a graph on what ... because rubber has hysteresis: unlike steel ... travel a section of rough road w/ an accelerometer-equipped trailer ...

Accelerometers used to hard to find outside a lab, but modern solid state versions are in IPhones, etc... there may be IPhone applications suitable for this already.

The last sentence is doubtful.

Who do you think your audience is? The people around here that already understood a damping function have already drawn their conclusion on the viability of shock absorbers on an Airstream.

Since you posted no conclusion, you may want to direct readers to the wiki(s) from which your statements were derived so all inclined to can understand everything involved.

Tom

[Jim & Susan]

The ground finally dried out enough around the camper so that I could crawl underneath and get a couple of pictures. Looks like you were correct, we (or more precisely, Ron) welded those arms much closer in to the frame than the factory did with yours. There's still a bit of cant, but not too bad. I should think that you can cut those arms off and move them inward without too much trouble (Of course, I'm assuming that you have, or know somebody that has, the right equipment to do so). This is the curbside rear wheel.

I have not read Atlas Shrugged but am very familiar with the basic thesis of the book. Given current events, the concept of Producers, Looters and Moochers seems to have a lot applicability to reality, doesn't it?

Jim

[barts]

Originally Posted by TomW

The last sentence is doubtful.

A minute or two w/ google returns:

Robota Softwarehouse - iPhone AcceleroLog - View accelerometer graphs and log data with your iPhone

Who do you think your audience is? The people around here that already understood a damping function have already drawn their conclusion on the viability of shock absorbers on an Airstream.

Since you posted no conclusion, you may want to direct readers to the wiki(s) from which your statements were derived so all inclined to can understand everything involved.

I was hoping to make things a little clearer as to why shocks might be a good idea... but since I haven't taken any data (we're still refurbishing our Airstream) I wasn't going to come out and say "Yes, use shocks" or "No, they don't help much". I don't know how much force the shocks generate, how they're valved, etc. The fact that the same shock appears to be used on all Airstreams regardless of weight seems to indicate that they're not critical in this application.

For those interested in some technical links only tangentially related to the topic but having some handy pictures:
Second Order Dynamics - WolfWikis
ValveTypesSelection - ControlsWiki

- Bart