Trailer Modifications: Receiver Mount for Winch

[Anak]

I am going to try to do some trailer mods, and hopefully not end up finding myself building a completely new trailer from scratch.


The starting point is a trailer that I picked up used 5 years ago. It came with a mismatched pair of 3,500 lb axles, only one of which had brakes. But the axles had been converted to spring over, and they ran 6 lug wheels. For me those were good details as that meant better ground clearance & interchangeability with other trailer wheels I already had.


At this point the axles have been swapped for a pair of 5,000 lb (matching) axles, still running 6 lug wheels.



I am now working on strengthening the trailer and setting it up for winching up inoperative vehicles.


I decided I wanted to run a receiver mount winch. This means the winch is much less likely to get stored on the trailer, out in the elements. It also means the weight of the winch does not need to remain on the trailer tongue. And it means that I don't necessarily even have to have the winch. A second vehicle and a snatch block could also do the job. And the receiver could even serve a completely different function such as support a bike rack. So I worked on collecting pieces and materials accordingly.


Here is the trailer tongue as it sat:

I stripped it down and started my layout. I used 2x4x3/16" rectangular tubing for the receiver mount. I pushed everything as far forward as I could and yet still maintain clearance to swing the jack handle. My knuckles will eventually tell me if I pushed things too far forward. Here I have things in place for the first cuts. The amount of overage on the left side of the pic (right side of the trailer) is by design. That off-cut will become one of my upper supports.

Here is the gist of the idea, with some cardboard aided design:

That cardboard got transferred to a piece of 6" C-channel for an upper frame support gusset.

I totally messed up with my idea for cutting the upper gussets out of a piece of C-channel. In my mind each one is a triangle, and the material is wide enough to flip the pattern and cut the same triangle out of the other side. Well, that is the problem. I get the same triangle. But I need a different triangle because these triangles are 3 dimensional, not 2 dimensional. In hopes that someone else can learn from my mistake, here is what I did (Note the pattern is R/S Up--I added the lettering for the sides after I realized what was the problem):

And moving the pattern over to the other side you can see, I have the same triangle, R/S up:

Now, with the pattern (same piece of cardboard) turned L/S up you can see it will not allow both the R/S and L/S to be cut from the same section of C-Channel:

In order to cut both pieces out of one section of C-channel, it needs to be a long section, like this:

And of course I didn't have another piece of C-channel quite long enough. So, I spliced a piece in order to get to the point of having a pair of gussets:

 

[Anak]

I wasn't able to angle my gussets as low as I really wanted, and still go over the top of my 2x4 support pieces. I compromised on angle and interference. The interference meant I would have to do some creative fitting to get the 2x4 material to match up with the rounded corners, at an angle, on the inside of the gussets. This is what the end fitment ended up being:

Here is the first mock-up showing the gist of the entire assembly:

I cut my riser to a height 1" above the front of the trailer deck rail. That was my guess as to what it would take to have the winch fairlead end just up high enough to have a chance of not always dragging the cable over the deck rail. I then cleaned up the rust off that part (it was a remnant I already had on hand) and welded up my riser:

With the lower crossbar clamped in place I centered my riser and welded it to the lower crossbar:

Then I added in the upper crossbars:

This allowed me to make a trial fit of the winch. It does indeed have the height to clear the top of the deck rail:

And it has at least 4" in front of it, which is enough to remove the winch from the receiver mount if the vehicle on the deck does not interfere.

 

[Anak]

Having fitted things up I then removed the entire assembly, welded the undersides and sprayed weld-thru primer on the sections which were going to become totally inaccessible in the future:

I then tacked it into place:

And finally I added the gussets:

In case anyone else cares, weight was something I was keeping in mind while doing this. My hope was that I could keep this mount under 50lbs. I weighed my assembly when I pulled it out for final welding, and it came in right at 30 lbs:

I also weighed my extra gusset, and it came in at 11lbs:

So that would make for a total weight of 52 lbs. Not too far from the target.


I still have a couple pieces to make before I can re-run my wiring and call this modification done. That will be for another day.


I also had to provide technical advice to a couple of Varmints during the project. Varmint #1 was working on cleaning up the interior of his own XJ, with some help from Varmint #Last: