Originally Posted by jaojamjab
You say that torsion axels can last 30 to 40 years "IF" properly used. If not they can fail in 3 or 4 years. What improper use would cause them to fail so soon assuming your set up properly?
All torsion axles have rubber rods in them. As long as the trailer is towed a few miles a couple of times a year, the axles will last a long long time.
Rubber must be exercised to stay alive. If not, the rubber can soften or harden like a rock. When a loaded torsion axle, is not used for 3 or 4 years, the rubber rods will die, from lack of use.
If the trailer will not be used for an extended period of time, it should be jacked up and supported with "jack stands". That will remove almost all the weight and stresses from the rubber rods, which will give them a fighting chance to stay alive.
The other thing that kills a torsion axle, is overloading it for an exteded period of time. If the axle is rated at 3000 pounds, as an example, long term overloading it will cause the rubber rods to fail.
That overloading can come from excessive weight in the trailer, or it's weight rating exceeded by a bad design from original production.
As an example, a 61-62 Safai used a 3600 pound torsion axle. A 63-64 Safari used a 4000 pound axle, and a 65-68 Safari used a 5000 pound axle, yet basically, they are all the same.
The changes were made because it was determined that the lower ratings were easily exceeded, causing axle failures. As a result, the weight ratings were increased in later models of the same trailer.
The same problem occurred with many early models from the Bambi's and Caravels on up to and including the 30 foot trailers.
More recently, some 34 foot models also had axles that were under rated.
When torsion axle/axles are replaced, their ratings, within limits, can be increased to eliminate the overload issues and problems. However, there is no flat rule other than do not exceed 10 to 12 percent increase from the original rating, without undertaking some beef up modifications.