Dura-Torque Explained

[TomW]

I found this article in the August, 1989 edition of Airstream Caravanner magazine, and thought it would be a nice addition to the archives. While the image contains "continued on next page", that page is not included as it only listed Service Centers.

Tom

[balrgn]

Very Nice!

[Hammer]

Thank you Tom W1
Mike

[BillTex]

Pretty cool design...
What happens when the rubber wears and the inner axle overrides the rubber?
Obviously it is time for replacement, but what if you are far from home?
Can you drive like this?

What design are the axles on my 89?

Thanx for the info, Bill

[Inland RV Center, In]

Originally Posted by TomW

I found this article in the August, 1989 edition of Airstream Caravanner magazine, and thought it would be a nice addition to the archives. While the image contains "continued on next page", that page is not included as it only listed Service Centers.

Tom

The following article tells you how to check your torsion axles.

Dura Torque Axle

Andy


NOTICE.

We have changed hosts, therefore some things may take a little time to correct themselves.

Andy

[BillTex]

Originally Posted by Inland RV Center, In

The following article tells you how to check your torsion axles.

Dura Torque Axle

Andy


NOTICE.

We have changed hosts, therefore some things may take a little time to correct themselves.

Andy

Thanks Andy, I was confused as the diagram did not show any shocks-my axle has shocks!
If your torsion arm angle is biased toward positive (a sign that your axle is going) is it also true that your wheel height relative to the body/wheel well will be changed (the wheels will be up inside the well?)
Would you also notice a rough ride/bottoming out?

I checked my axles and the torsion arms are what I believe to be positive angle-not good! Unless I am interpreting this backwards…

Here is what I see;
Torsion arm angle is up (rear “\” front not rear“/”front) going toward rear of camper, but wheel to wheel-well height is fine and ride of camper is fine.
I also believe that this camper does not have a lot of miles/use. (All other signs are of minimal use; body, interior, upholstery, etc)

Am I interpreting this backwards?

Thanx, Bill

[Killo1]

Very Informative.
Thanks

[Inland RV Center, In]

Originally Posted by BillTex

Thanks Andy, I was confused as the diagram did not show any shocks-my axle has shocks!
If your torsion arm angle is biased toward positive (a sign that your axle is going) is it also true that your wheel height relative to the body/wheel well will be changed (the wheels will be up inside the well?)
Would you also notice a rough ride/bottoming out?

I checked my axles and the torsion arms are what I believe to be positive angle-not good! Unless I am interpreting this backwards…

Here is what I see;
Torsion arm angle is up (rear “\” front not rear“/”front) going toward rear of camper, but wheel to wheel-well height is fine and ride of camper is fine.
I also believe that this camper does not have a lot of miles/use. (All other signs are of minimal use; body, interior, upholstery, etc)

Am I interpreting this backwards?

Thanx, Bill

Bill.

Your describing torsion axles that are gone.

When torsion axle rubber rods fail, for whatever reason, the trailer "will bottom out." When that happens, many different damages can and will happen. I just talked to a fellow this morning, who wasn't aware of his axle problem, but now he knows. His problem, is that the frame and axle mounting plate are severely cracked. Cause? Bad axles.

When the rods go bad, the wheels rise into the wheel wells, which is the same thing as the trailer becoming closer to the ground.

Mileage has nothing to do with the rods. Lack of mileage, which means little to no rubber rod movement, will cause a set to take place. Some owners have learned that the hard way, even on trailers less than 5 years old.

From 1974 and older Airstream trailers, the rods were made with composition rubber rods, that within themselves, would fail.

Additionally, if any torsion axle has a load imposed upon it, such as that caused by parking the trailer for a long period of time, the rods will take a set becasuse the rubber was not exercised.

Torsion axles must be exercised. If not, they will take a set.

That set can be avoided, when a coach will be parked for a long period of time, by taking most of the weight "off" the axles, using lifting type jacks, or jack stands, placed on the frame.

Stabilizing jacks cannot lift enough weight off the axles to avoid the problem.


Andy

[Smokin Camel]

Andy, I am going to remember your tip after I get the new axels installed. You did say put thejacks on the frame...any tips on where and how much pressure? I realize that this is sort of a generic question and there will be some variety according to the trailer size. In my case the old camel is a 25' dual axel.

I am assuming that the lifting jacks should relieve pressure and not lift the trailer very much???? Common sense tells me near the wheels but I have been wrong before!

Also thanks for all of the extra help you gave me. I will document the installation, if a somewhat disabled type like me can do it that should tell the able bodied something! I am actually looking forward to the project (plus getting on the road again).

[BillTex]

Originally Posted by Inland RV Center, In

Bill.

Your describing torsion axles that are gone.

When torsion axle rubber rods fail, for whatever reason, the trailer "will bottom out." When that happens, many different damages can and will happen. I just talked to a fellow this morning, who wasn't aware of his axle problem, but now he knows. His problem, is that the frame and axle mounting plate are severely cracked. Cause? Bad axles.

When the rods go bad, the wheels rise into the wheel wells, which is the same thing as the trailer becoming closer to the ground.

Mileage has nothing to do with the rods. Lack of mileage, which means little to no rubber rod movement, will cause a set to take place. Some owners have learned that the hard way, even on trailers less than 5 years old.

From 1974 and older Airstream trailers, the rods were made with composition rubber rods, that within themselves, would fail.

Additionally, if any torsion axle has a load imposed upon it, such as that caused by parking the trailer for a long period of time, the rods will take a set becasuse the rubber was not exercised.

Torsion axles must be exercised. If not, they will take a set.

That set can be avoided, when a coach will be parked for a long period of time, by taking most of the weight "off" the axles, using lifting type jacks, or jack stands, placed on the frame.

Stabilizing jacks cannot lift enough weight off the axles to avoid the problem.


Andy

Hi Andy, with your additional info I crawled back under there tonight; camper has been sitting since for about 2 months since last moved. Torsion arms, according to the diagram, are maybe 5-10 deg negative, which is good, but not by much. Wheels do not appear to be receeding into wheel well, camper does not sit too low.

Is this normal for a 25' of my vintage ("heavy") after sitting for a couple of months? (Camper is in winter mode, no fluids, but still lots of other stuff; all the appliances,etc)

Towing, the ride seems smooth as silk...
I will check the offset when we move her again in a month or so...
Next year, I will use jack stands for the winter...
As Smokin asked "where exactly to place jackstands"?

Thanx for your expertise,
Bill

[BillTex]

Good morning Andy, any response on our last 2 posts?

Sure could use the info...

Thanx again, Bill

[Inland RV Center, In]

Originally Posted by BillTex

Good morning Andy, any response on our last 2 posts?

Sure could use the info...

Thanx again, Bill

Storing a torsion axle trailer long term, is very different from "spring" suspension systems.

Place a jack under the axle mounting plate. After most of the weight is off the wheels, place a "jack stand" under the axle mounting plate, rearward of the "rear" tires. For a larger trailer, you can also place a jack stand forward of the front tires, again at the bottom of the axle mounting plate.

"DO NOT" attempt to lift the trailer with the stabilizing jacks. The are not designed for that stress and will quickly break.

Storing a "lifted" torsion axle trailer for years, will have no "ill" effect on the rubber rods, but instead, will preserve them.

Andy

[Inland RV Center, In]

Originally Posted by BillTex

Hi Andy, with your additional info I crawled back under there tonight; camper has been sitting since for about 2 months since last moved. Torsion arms, according to the diagram, are maybe 5-10 deg negative, which is good, but not by much. Wheels do not appear to be receeding into wheel well, camper does not sit too low.

Is this normal for a 25' of my vintage ("heavy") after sitting for a couple of months? (Camper is in winter mode, no fluids, but still lots of other stuff; all the appliances,etc)

Towing, the ride seems smooth as silk...
I will check the offset when we move her again in a month or so...
Next year, I will use jack stands for the winter...
As Smokin asked "where exactly to place jackstands"?

Thanx for your expertise,
Bill

Bill.

Check the position of the torsion arms, when the trailer is fully loaded.

When fully loaded, the torsion arms must not go above parallel to the chassis. If they do, then the party is over.

Additionally, even parallel torsion arms, suggest some deterioration of the rubber rods.

Andy

[BillTex]

Originally Posted by Inland RV Center, In

Bill.

Check the position of the torsion arms, when the trailer is fully loaded.

When fully loaded, the torsion arms must not go above parallel to the chassis. If they do, then the party is over.

Additionally, even parallel torsion arms, suggest some deterioration of the rubber rods.

Andy

Thanks Andy, I will check position after we move her again in a month or so..

What is "average" life of an axle?
Is 18 years about due?

If Henschen will not rebuild after 20 years, am I better to rebuild now (18 yrs old) or just replace with new in a year or two?

Can any AS dealer do this?

Thanx again, Bill

[Inland RV Center, In]

Originally Posted by BillTex

Thanks Andy, I will check position after we move her again in a month or so..

What is "average" life of an axle?
Is 18 years about due?

If Henschen will not rebuild after 20 years, am I better to rebuild now (18 yrs old) or just replace with new in a year or two?

Can any AS dealer do this?

Thanx again, Bill

The life of a Henschen torsion axle, from 1975 and newer, is unlimited, under normal use.

Unfortunately, the rubber rods used from 1974 and older, are all failing. It's just a matter of time.

The rubber rods will take a set, rendering them bad, on "any" torsion axle, if it's under an appreciable load, and put in dead storage for an extended period of time. That time is usually 3 to 4 years.

Many years ago, Henschen would rebuild an axle. That practice ceased some time ago, primarily because of liability factors.

Therefore, if the torsion axle is bad, it must be replaced. Rebuilding is no longer an option.

Henschen axles used from 1969 and newer Airstream and Argosy trailers, are "direct bolt in" replacements. No changes are needed.

Those axles can be replaced by most anyone, that has a few shop tools, like a jack, and a socket set, or crescent wrenches. A jack is not needed except when changing the axle on a single axle trailer. Tandems and tri-axle trailer axles can easily be replaced without using a jack of any kind.

It is not necessary to use a dealer.

Many owners replace the torsion axles themselves.

The hardest part, is disposal of the old axles.

Andy

[BillTex]

Originally Posted by Inland RV Center, In

The life of a Henschen torsion axle, from 1975 and newer, is unlimited, under normal use.

Can I assume then that the 5-10 negative angle on mine is OK and that this is typical for a heavy (1989) camper that has been sitting in winter storage?

You have seen way more AS's (is that PC??? ) than I have and must have some idea what the normal angle is?

What is the typical angle when brand new?

I have yet to see a post about raplacement on newer AS axles, they are usualy, as you stated, on the older models...

Bill

[Inland RV Center, In]

Originally Posted by BillTex

Can I assume then that the 5-10 negative angle on mine is OK and that this is typical for a heavy (1989) camper that has been sitting in winter storage?

You have seen way more AS's (is that PC??? ) than I have and must have some idea what the normal angle is?

What is the typical angle when brand new?

I have yet to see a post about raplacement on newer AS axles, they are usualy, as you stated, on the older models...

Bill

Bill.

We have sold many replacement axles for Airstream trailers that are year 2000and newer.

The cause is always the same, other than an accident. Long term storage "without" removing some of the weight from the axles.

There is "no" normal position of the torsion arm, since it is weight sensitive.

The empty, typical brand new Airstream trailer, will have a starting angle of about 15 degrees. That will decrease as you add "pay load" to the trailer.

The number of Airstream owners using this site, let alone posting on it, is not a high percentage, unfortunately.

Accordingly, information posted on the newer years by the owners, is not very much, again, unfortunately.

Andy

[BillTex]

Andy-thank you once again;
You are a wealth of AS knowledge!

Sincerely,
Bill

[Smokin Camel]

Andy; Thanks for the storage information. I will put it to good use next fall.