Originally Posted by mandolindave
"1. How much of the tire can you see above the top of the wheels? It should be at least 2 inches."
Andy, I am confused by this. Can you reword this for dopes like me?
There are two ways to quickly determine the basic condition of the Henschen torsion axles installed by Airstream since 1961
1. Read the following article.
Dura Torque Axle
2. Stand about 20 feet away from the side of the trailer, and stoop down. Then look at the tire and wheels. You should see about two inches of the tire, ABOVE
the top of the wheel.
If it's less than that, then the axles are questionable.
If you cannot see the top of the wheels, then the axles are finished, with absolute certainty.
There is one other test that can be made, that requires a jack for single axle trailers. Place a mark the tire even with the wheel well. Jack up that side of the trailer and note how much the tire drops. It should drop at least 2 inches or more. If not, then the rubber rods have solidified, which will give the trailer a rough ride. That roughness will damage the trailer, therefore the axle should be replaced.
In the case of a tandem axle trailer, mark the tires on one side as above. Pull one tire up on some blocks, that are at least three inches high. make the same observation as above. Then pull the other tire up one the same blocks and make that same observation. The tires should drop at least 2 inches or more.
If the trailer is leaning to one side, make the test on the side that is closest to the ground.
In the case of a tri-axle trailer, do the same tests as in the tandem axle, but do it for all three tires on one side of the trailer.
All the tires should drop the same amount on a tandem as well as a tri-axle. If not, then the tire or tires that drop the least, indicate that one or more axles may be bad.
If that's the case, then one must determine the condition of each axle by making all the observations.
If one axle is bad, and the axles have been in service for a few years or more, then all the axles must be replaced, as it's impossible to mate a new axle with an old axle, and expect then to do an equal job. They cannot and will not, since in time, you can almost be certain that the axles have somewhat settled closer to the ground.
The keys to longevity are two fold, and simple.
The rubber rods must be exercised frequently, like every year or more, for at least a few hundred miles.
If not, the rubber rods can and will settle.
If the trailer has been parked without removing most of the weight from the axles for an extended period of time, such as a couple of years or more, you can almost bet that the rubber rods have settled. If the trailer will be stored for an extender period of time, like a year or more, most of the weight should be removed from the axles.
Lastly, even if most of the weight has been removed from the axles, is still no assurance that the rubber rods will not solidify. They might and they might not solidify. There is no way to predict the behavior of those rods.
Experience does suggest however, that removing most of the weight, will add to the life expectancy of the rubber rods. How much?? No one knows with any degree of certainty.
Hopefully, this answers your question.