I have owned my utility trailer for about 20 years - and it looked as used/old then as now. This is a light duty trailer - axle was from a Honda 600 (cut in half and sleeved with a tube, I replaced the 10 inch dia wheels w/ 13 inch RX7 wheels when it became harder to source 10 inch tires) - that I occasionaly load up to 1 ton. Twice the trailer coupler became disconnected from the ball. Once about 8 years ago while traversing some railroad tracks on a dirt road (possibly at a bit too high of speed!), and once again recently. Both times the trailer was empty. After each event I tightened the adjustment nut on the coupler - the last event surprised me since after the first unintentional disengagement I checked and adjusted the coupler so that it just dropped over the ball. Now it is *very* difficult to get the coupler over the ball. I do not know the brand of coupler - probably about 30 years old, lever locking style.
My father has a trailer where there the coupler has a knob to draw up the coupler tounge instead of a lever. I looked but I have not had any luck in seeing any of these still available for purchase. While this style requires more disipline on the part of the trailer user, I feel that I could adjust the tounge for less clearance to the ball than the lever locking style.
Since my coupler is for a 1 7/8 inch dia. ball, I figured I could solve both the anoyance (sp) of switching balls and upgrade to a more robust coupler. So my question is: who makes the best coupler? Class 2 as a minimum - although all the links below are Class 3. Brands that I have found include: Valley, Atwood, Fulton.