A quick (and not always accurate) test is to look at the side of the wheel/tire. If the body of the trailer has settled enough to cover the entire top of the tire to the edge of the top of the wheel, it is time for axles. Even if it is close. And on a 34 year old trailer that has not been used ...... plan on it. The non-use is worse that than hard use.
There will be no sudden failure of these types of axles.
1966 Mercury Park Lane 4 DR Breezeway 410 4V, C-6, 2.80 - Streamless.
1966 Lincoln 4 door Convertible 462 4V 1971 Ford LTD Convertible 429 4V Phoenix ~ Yeah it's hot however it's a dry heat!