I got a trailer that is 43 years old with torsion axles on it. What is the lifespan on a axle of this type? They don't show any issues just trying to be cautious.

Look for rust or flaking in the tubes. If no sagging and still move free you should be OK.

Didn't know they had torsion axles back in those days. You sure they weren't put on recently?

I know they used them on tanks during World War II.

The torsion rubber is good for about 20+ years. My guess is they were replaced as I do not know ANY boat trailer manuf putting them on 40 years ago. What brand trailer?

Wannabe

It's a 1968 Thunderbird. Found another (I think 1970) Nova with its original trailer and it was set up the way. Now they both could've been changed over the years but being there was only 124 made originally and I've only found eight so far they would be some long odds that the same thing happened to both trailers so I think it's original.