OK, done with this one.
I removed the ball coupling off the trailer.
Installed an eye instead. Bolted the eye assembly under the frame and holding it with 3 half-inch grade 8 bolts and 2 nuts each. I'm pretty sure this should be plenty strong. If not, I have prepared a system with a steel sleeve that I'd weld the eye assembly to and then slide over the main beam of the trailer frame. I'd hold this with a hitch pin across the whole thing, and could put it either on top or bottom of the frame in a few seconds, or remove it for safekeeping.
But anyway, I just bolted it in for now. This was quite a job, to get all the holes to be positioned right etc, especially when I discovered belatedly that the PO had not drilled a couple of holes in the frame straight....
And had to be careful not to interfere with the moving shaft of the eye etc...
The eye is full swivel and is damped axially by 2 heavy duty springs (1 in each direction) to help with shock absorption. Very heavy duty. I can also bolt the assembly on top of bottom of the frame. For now, on the bottom, the trailer is only 1.5" lower at the very front than at the back. When I put a lift on the truck it'll be slightly nose up. The inside of the bottom horn of the pintle hook is 19" from the ground. Plenty of ground clearance on all this. I have something like 17" of ground clearance under the axle (yea!)
The beauty of this pintle hook system is that after a long search I was able to find a pintle hook that would not interfere with my exisiting receiver. There is probably only 1/64" or less between the hook and the 2" tube, very very close. (The pintle hook is a PH8 from Buyers products. The receiver is a DrawTite with the 2" tube even with the mount, not lower, much better for clearance....) So I have both the receiver and the pintle on for more flexibility (and protection). The pintle does also project just enough beyond the receiver than I have something like 70 deg articulation downward.
I put on the hook with two 8.8 bolts (can't find the dang 12x1.25 size in 10.9) in the threaded holes and 2 half-inch grade 8 in the lower holes. Should be plenty strong. I'll only tow my offroad trailer with this setup, probably only 2000 lbs or less.
So all in all, I'm happy. In retrospect, having taken the trailer offroad with a ball was just plain silly. It gave me stomach cramps everytime I heard weird croaking while going through creeks etc. The pintle / eye system is vastly superior for offroading. No comparison...!
I removed the ball coupling off the trailer.
Installed an eye instead. Bolted the eye assembly under the frame and holding it with 3 half-inch grade 8 bolts and 2 nuts each. I'm pretty sure this should be plenty strong. If not, I have prepared a system with a steel sleeve that I'd weld the eye assembly to and then slide over the main beam of the trailer frame. I'd hold this with a hitch pin across the whole thing, and could put it either on top or bottom of the frame in a few seconds, or remove it for safekeeping.
But anyway, I just bolted it in for now. This was quite a job, to get all the holes to be positioned right etc, especially when I discovered belatedly that the PO had not drilled a couple of holes in the frame straight....

The eye is full swivel and is damped axially by 2 heavy duty springs (1 in each direction) to help with shock absorption. Very heavy duty. I can also bolt the assembly on top of bottom of the frame. For now, on the bottom, the trailer is only 1.5" lower at the very front than at the back. When I put a lift on the truck it'll be slightly nose up. The inside of the bottom horn of the pintle hook is 19" from the ground. Plenty of ground clearance on all this. I have something like 17" of ground clearance under the axle (yea!)
The beauty of this pintle hook system is that after a long search I was able to find a pintle hook that would not interfere with my exisiting receiver. There is probably only 1/64" or less between the hook and the 2" tube, very very close. (The pintle hook is a PH8 from Buyers products. The receiver is a DrawTite with the 2" tube even with the mount, not lower, much better for clearance....) So I have both the receiver and the pintle on for more flexibility (and protection). The pintle does also project just enough beyond the receiver than I have something like 70 deg articulation downward.
I put on the hook with two 8.8 bolts (can't find the dang 12x1.25 size in 10.9) in the threaded holes and 2 half-inch grade 8 in the lower holes. Should be plenty strong. I'll only tow my offroad trailer with this setup, probably only 2000 lbs or less.
So all in all, I'm happy. In retrospect, having taken the trailer offroad with a ball was just plain silly. It gave me stomach cramps everytime I heard weird croaking while going through creeks etc. The pintle / eye system is vastly superior for offroading. No comparison...!