The design life of a rubber torsion axle is about 20 years. That said, many make it to 30, but few make it past that. The axle arm should be horizontal with the trailer frame or even have a slight down angle if it's still good. If it's pointing up toward the floor, the odds are it's bad.
A quick check is that you ought to be able to see most of the tire sidewall in your wheel well. The less you can see, the less competent your axle is.
AIR 2053 Current: 2006 Born Free 32 RQ Kodiak Chassis, & 1995 Coachmen B-van
Former Airstreams: 1953 Flying Cloud, 1957 Overlander, 1961 Bambi, 1970 Safari Special, 1978 Argosy Minuet, 1985 325 Moho, 1994 Limited 34' Two-door, 1994 B190 "B-Van"