Anyway, I noticed that if I come to a stop while driving forward, the tongue remains compressed. When I release the hitch and crank it up, the tongue ever so slowly extends back to full forward. This probably means I need a new strut...

In my older Cobra trailer, that's normal behavior. The damper just prevents the tongue from slamming the brakes full on in a hard stop. It also prevents the tongue from hitting the stop in fully expanded position in hard acceleration. It is, in fact, very much a shock absorber, not a spring.

That's not to say that later models don't have gas springs; I wouldn't know.. But I would think it would make more sense to use a coil spring with progressively higher force the more the tongue is compressed rather than a gas spring with its nearly linear force/deflection profile. But I'm not an expert.

If you can deflect the strut by hand by slowly compressing it, and if it's about as difficult to expand as to compress, it's a damper. You'll know if it's a spring: lots of force in one direction and if you let it go, it expands quickly to its free length.

The nice thing about the damper, at least in my trailer, is that you just unbolt the tongue, including one end of the damper, and slide out the moving, inner (piston) tube. Bolt in the new damper on one end, then insert the tongue and slowly compress it by hand while peering into the hole in the tongue for the other end of the damper. When it finally comes into view, insert a punch to line everything up, then insert the bolt. It's literally a 5-10 min. operation after you've done it once.

The older Eberle trailers didn't have anything, as I recall. In a hard stop, the trailer brakes would come on suddenly causing the trailer wheels to briefly lock up, especially on uneven pavement when a panic stop would cause the wheels to lock up and bounce, chirping madly every time they touched the ground. Those are also the ones where you had to get out and set the locking lever in the tongue to allow you to back up without actuating the trailer brakes.

Chip Bearden
ASW 24 "JB"
U.S.A.