I check often when I hookup my trailers by cranking up the tongue jack and make sure the couples doesn't come off.....make it a habit ! Especially one new to you trailers.
I tow trailers that are not mine to adjust. I frequently run into 2 different situations with safety chains. The first is too long which is easy to fix by twisting the chain a couple of times. The other is too short. Usually long enough to connect but too short to cross. Occasionally they won’t reach to connect (I think those were cables).
Actually, there are three. Some trailer manufacturers route the wire harness through the left safety chain which limits what can be done with it. One of my trailers is that way…I need to fix it. The chains are long enough to cross but the lights cannot be connected if I do.
Back when I worked at a marine dealer, I often towed trailers that were not mine. I carried a couple lengths of chain and quick connects along with a pigtail extension just in case. Used them often as there is no standard for lengths of chains or pigtails. However, if a coupler needs adjusted to keep from coming off the ball, it gets adjusted or I don't pull it, no matter whose trailer it is.
