Rubber torsion axles: durability and fixability?

[e9999]

I was looking at a small travel trailer yesterday. It has a rubber torsion axle. Which made me think about whether that is a good or bad thing. I'm reading that some are quite durable but I don't know about the good and bad design variations. But mostly I was thinking about what happens if it were to go bad. With a broken leaf spring, at least, it's easy to replace and inexpensive. With the rubber torsion axle it seems like you would have to replace the entire axle assembly since presumably the rubber inserts are bonded with some fancy stuff in the housing.
Thoughts? A design to avoid in a used trailer?

 

[Brian in Oregon]

Durability "on road" may be quite different from durability "off road".

 

[ntsqd]

My trailer, prior to my owning it has made many trips to Baja and one trip to Mexico's Copper Canyon. Since then I've taken it to the Oregon Dunes, Panamint Valley, "glamping" in Joaquin Suave's front yard, and to a couple desert races. Never had an issue. The singular, only issue that I have ever heard of with rubber torsion axles was reported by Adventure Trailers. It was a show stopper that probably wasn't an easy fix. While one exception disproves a theory we can't live in fear of everything that could happen either. The AT issue can be addressed with a pair of simple straps bolted in place such that the should the trailing arm de-vulcanize from the housing it still can not escape and leave you stranded.

I do strongly suggest adding shocks to the system. It is my unproven theory that since heat is the easiest way to achieve de-vulcanization that washboard & rough road operation requires a heat sink to keep it out of the rubber.

 

[skersfan]

Ihave had this discussion many times. I have asked repeatedly for picutres of this famous failed axle, that Dexter Torflex manufactured. To this day and having asked for over 6 months, still no picutres of a failed axle under warranty. According to Dexter Torflex, this failure never occurred.

As to the strength of the axle, I only ask that you find out what NATO and the US Armed forces use. You will find on all trailers smaller than 5K they have convered to Dexter Tor Flex and Alko rubber ride axles. My guess is that the Marine Corps and Army have a few more testing hours on these axles than a samll manufacturer does.

These are state of the art axles, cost more than building them your self drag along boxes with shocks and rubber bags.

The Army and Marine Corps will be using the new Dexter Tor Flex on their new 10K trailers, but only on Dual axle trailers. Tri Axles are not recommened, but that has no affect on our needs.

I have worked with Dexter for many years, have never seen an axle fail, and that would be using well over 500 axles.

Research what axle you have under your trailer, if it is a Dexter or Alko, you should be good to go, the other ones that just mount to one sie are a disaster just waiting I think. But then again I have never seen one of those fail either.

 

[ntsqd]

There was a picture of the failed axle posted on Expo. This was in the trailer section, but before their server change. No idea if it survived the change or not, but it would date back to slightly before my same user over there was registered because it existed when I joined and was cross-posted a couple times.
Since the trailer in question was a friend or acquaintance of AT's I've no doubt that it was replaced with one of their suspensions. That Dexter was never notified of this would not surprise me.

 

[Michael Hanson]

If they held up carring my 4 horses they will be fine for most folks. Mike

 

[LandCruiserPhil]

The Dexter axle will first change camber or toe in long before any catastrophic failure from normal use within its rating. I know of 2 examples (Venturcraft and Kwik Kamp) and trailers were under 1000# and 600# GVW .

 

[e9999]

am I right to assume that rubber torsion axles in general can not be fixed if/when they do fail?

I don't think the one I saw was a Dexter. I don't remember the manufacturer but the tag did not say Dexter. It had an odd cross section, not circular, more like a pear shape IIRC.

 

[ntsqd]

The infamous failure reported by AT was a de-vulcanization of the rubber from the steel. That allowed the trailing arm assembly to move laterally out of the axle housing. Once de-vulcanized it's pretty much done. It is possible to remove the rubber, prep the steel, and replace the rubber, but it takes specialized knowledge, chemicals & tools that few companies have, much less any private party.

 

[Woodsman]

My only experience with these is on my 7 x 14 cargo trailer which has the two Dexter brand torflex axles. This rides super smooth and takes holes with grace unlike the violence you may witness with sprung trailers. On single axle trailers they seem to ride much smoother with less bounce, IMO. Of course, you also gain some ground clearance.

The one thing that could use improvement is their coatings. After eight years, the axles are heavily rusted (i.e. absolutely no paint remaining) and may need to be replaced only because they are looking pretty ugly where they are welded to the trailer frame. In their defense, this is probably typical especially in our land of road salt and calcium chloride.

 

[skersfan]

Woodsman, the axles have be pretty old if they are welded directly to the frame. I saw a couple of those when I first started using them, and Alko had a few. Tha was late 1986 I think. They went to a bracket and now bolt to the bracket in case of damage.

In honesty I was never impressed with the Dexter appearance either, but I have all my frame Rhino Lined and that includes the axle.

For all of us serious off roaders, I think a small eyelet welded to the trailing arm and one to the frame, would allow for a tie down or chain to be placed there in case of emergency. I am going to do more research on this as Dexter states over and over they have never seen this failure, no warranty was requested. I do know that there was like axle being made back then and it was made in Mexico, looked almost exactly like the Dexter, but I can not remember the name.

 

[Woodsman]

The brackets have bolt holes but they welded all the way around the perimeter of the bracket.

I will likely spend the dollars to rework the trailer sometime, especially if I start taking loads to Jersey/Maryland again in the future as I did pre-crappy economy. This will include new axles, wheels, tires and I will stand it on end and blast and coat the frame. Either way, I love the Dexters.

 

[skersfan]

I have used them since the first ones hit the states, Alko was actually first on the continent, but were out of my price range. I used several of them back then but at 800 bucks a pop and having two on most of the trailers I had to find an option. I went with Dexter and have used them for 25 years, never seeing an axle failure, other than outside forces causing them. Phil Duckworth is the National Sales manager for them and he was my original salesman, both of us just starting out. I have told him over and over about this failure, and he asks me for proof of it. I have asked AT and they have not forwarded any proof, IE pictures. But it really has gone on long enough. I will find out what really happened.

Anything can fail, and anything can cause something to fail, but according to Dexter devulcanization can not happen, and has never happened. I need to get to the bottom of it as it is the suspension system I use and have for a long time. I have supported them for many years, I want to be sure what I am doing is the best on the road/off road. With the US Military and NATO using Dexter and Alko for all trailers, my guess is they are pretty good, as people lives depend on them, not so much the wine bottles or eggs.

 

[deepmud]

I remember seeing the pics on A/T as well - I always thought it was a combination of heat (chatter bumps) and dust getting in the rubber springs, causing friction. I don't recall them calling the rubber torsion axle a "Dexter" specifically. I have rubber torsion springs on my rig-hauling trailer, which originally was an RV trailer that someone cut the top off of. It's pretty old, and works fine. I'd agree that for sustained use on dirt roads one should think about adding some shocks. I doubt that slow speed rock crawling effects them much at all.

As to leafs being "easy to fix" - I think someone capable of welding/repairing leaves could weld/repair/strap up a torsion axle well enough to limp home from anywhere in North America. I'd rather have something more like A/T's current suspension if I were to travel Pakistan or something, because it's spring/support is accessible and could be jury-rigged with a Ready-Welder or similar, while the soft ride would tend to avoid being beaten to death in the first place (my read up on the Lone Wolf Expedition makes me want to avoid leaf springs and ALWAYS bring a welder if I was driving around the world).

 

[e9999]

I remember seeing the pics on A/T as well - I always thought it was a combination of heat (chatter bumps) and dust getting in the rubber springs, causing friction. I don't recall them calling the rubber torsion axle a "Dexter" specifically. I have rubber torsion springs on my rig-hauling trailer, which originally was an RV trailer that someone cut the top off of. It's pretty old, and works fine. I'd agree that for sustained use on dirt roads one should think about adding some shocks. I doubt that slow speed rock crawling effects them much at all.

As to leafs being "easy to fix" - I think someone capable of welding/repairing leaves could weld/repair/strap up a torsion axle well enough to limp home from anywhere in North America. I'd rather have something more like A/T's current suspension if I were to travel Pakistan or something, because it's spring/support is accessible and could be jury-rigged with a Ready-Welder or similar, while the soft ride would tend to avoid being beaten to death in the first place (my read up on the Lone Wolf Expedition makes me want to avoid leaf springs and ALWAYS bring a welder if I was driving around the world).

when I was asking about fixability of springs vs rubber, I didn't mean fix a broken spring with welder and such, but rather replacing it, which is a matter of a few bolts, fairly inexpensive and probably easy to find just about anywhere, vs (I guess) replacing an entire rubber torsion axle from side to side, which I imagine is much costlier and more difficult to arrange. Now, of course, if everybody agrees that rubber axles rarely if ever fail, then potential fixability is more of a moot point. What did prompt the question in part was seeing that the rubber bushing / cover (?) at the end of the bushing appeared deformed/cracked, which made me wonder about the condition overall.

 

[skersfan]

Could some one post this picture. I am not able to find it. Dexter wants to see it.

 

[skersfan]

Feel safe Deep Mud, as every US Army trailer, US Marine Trailer and Air force trailer will have a Dexter Torflex axle under them. Not springs, Not a trailing arm suspension with air bags, but a Dexter TorFlex just like the ones you can buy from them.

Now the new 5000 pound axles and above come with an air bag syste in addition to the standard TorFlex system, unfortunately they are not bringing it to the smaller trailers at this time.

The reason all of these old military trailers are becoming available as they are being phazed out and are being replaced with this type of axle/suspension system.

 

[deepmud]

when I was asking about fixability of springs vs rubber, I didn't mean fix a broken spring with welder and such, but rather replacing it, which is a matter of a few bolts, fairly inexpensive and probably easy to find just about anywhere, vs (I guess) replacing an entire rubber torsion axle from side to side, which I imagine is much costlier and more difficult to arrange. Now, of course, if everybody agrees that rubber axles rarely if ever fail, then potential fixability is more of a moot point. What did prompt the question in part was seeing that the rubber bushing / cover (?) at the end of the bushing appeared deformed/cracked, which made me wonder about the condition overall.

You know, given that bajillion of them are on the road, I think you don't need to worry about them. Most likely a non-issue.

Easy to replace? Pretty much lift it up, swap in a new one. Cost? I don't know - not terrible. Not likely, I think, so not your primary reason for choosing the axle or not.

**************

Feel safe Deep Mud, as every US Army trailer, US Marine Trailer and Air force trailer will have a Dexter Torflex axle under them. Not springs, Not a trailing arm suspension with air bags, but a Dexter TorFlex just like the ones you can buy from them.

I gotta be honest, Skersfan - your posts all over the net look like damage control to me - like you have an interest in Dexter. I think if you had left it alone there would be less "noise" on the net about the rubber axles - IMHO. That is to say, I've seen more posts about them in the last year or so, with you defending the rubber torsion idea, and you keep mentioning the military using them. I didn't know Dexter made any before you posted.

And the fact that the Army uses it means that someone won a contract, not that it's the greatest thing since sliced bread.
It might very well BE a great product but it will interesting to see what happens over the long term - the military can be VERY tough on a product.

I do like the torsion axles but if i managed to destroy one somewhere that limp-home was not an option (Like a 3rd world country - I think 100 miles off-road in Alaska IS a place with limp-home option) then I'd want something I could make from junk parts - I could make a trailing arm OR I could make a leaf-sprung unit out of junk and welder.

I would certainly run a rubber-torsion style to just about anywhere in U.S., Canada, and likely Mexico. I might build my own A/T style too - 3rd choice would be leaf-sprung. I think a leaf-sprung trailer is harder to make both smooth/soft riding (easy on your gear/spindles/bearings) and good at heavy loads - I think as a rule they are chosen by manufacturers as cheaper.

These are just my opinions, your mileage may vary, I'm not an expert just a guy with some experience beating up stuff off-road, one 15k-mile trip from Alaska to D.C. and back hauling my homebuilt (with automotive suspension) trailer, plus a bit of automotive background (AA Automotive Degree and some years as a dealership mechanic). I have yet to break any trailer except a Fred Meyer's cheapo' unit and ANYONE can do that with just a little effort

 

[ntsqd]

The idea that grit intrusion was the culprit traces back to AT. I do not buy it. For grit to get between the rubber and the steel the vulcanizing would have already failed. Meaning that the grit intrusion was secondary and not the failure mode.

Since heat is the easiest way to de-vulcanize something I think that these axles should have shocks on them for any application, but an off-road application shouldn't be considered at all w/o them. Shocks turn motion into heat, so whatever the shocks dissipate is heat that the rubber torsion axle doesn't have to dissipate. Which will keep the temperature of the rubber lower than without shocks.

 

[skersfan]

Being a loyal follower of Dexter is not a problem. I just get sick and tired of hearing about this destroyed axle over and over and over and over and over and have never seen a single picture of it. I have asked Martyn publicly and privately for the pictures and still have never seen them. I want this information so I can confront Dexter with the photos and find out what did happen. We are taling about one or two axles that failed,two by one small trailer builder, out of the millions that they have sold. I think anyone trying to build a good trailer should know the facts about all types of suspensions. It has gone from failing to not protecting the wine bottles and eggs. I have been using my trailer for over 4 years on some very tough trails, still no failure and no broken eggs.

As to the long term, the Military has been using them for quite awhile, not sure how long, but saying long term would indicate a number of units. My guess is that the military with their hundreds of thousands of trailer gets more use in a single afternoon than all that have been manufactured by AT. We are talking small numbers. AT makes a great trailer, have a tremendous suspension system, have done adequate testing I am sure. But I doubt we heard about their testing failures on their own equipment, which just flat happens. But just in general saying the torsion axle is not good for off roading is about the most stupid thing I have ever heard.

I agree repairing one would be a problem, but mine will be built with the limp home fix if it should happen. I will weld eyelets to the fram and the trailing arm, so that a cable, tie down or chain could hold the axle from working its way out. Would not require a welder or anything special. I say this, because I was told the axle worked its way to the outside of the trailer, but stopping it from moving away from center it would fix the main situation.

I build trailers, I also build off road trailers. I use Dexter as my suspension system.

The contract was won by both Dexter and Alko, the reasons stated, they were superior to the antiquated equipment in the field and that peoples lives depended on them.

The fact that you did not know Dexter or Alko built this type of axle is one reason for my defense. These axles have been used in Euorpe for many many years, this is not a new type of axle, I have used them for over 25 years. I think Alko was the original producer in Euorpe, and I know some of the South African trailer manufacturers use the Alko for off road, one thatclaims to make more off road trailers than all the US manufacturers combined uses only Alko Torsion axles.