This is a project that I never really intended, but the trailer I bought to haul leaves and gravel turned out to need more work than I thought - so here is the project
Step 1: The Starting Point
I purchased a trailer that had been made from the back half of a pickup off craigslist for $100. It was a 3/4 ton chassis with a bed that I thought was good. Unfortunately the bedliner was covering the fact that the bed was completely rotted to pieces. Luckily, aside from a bad hub bearing the frame was in excellent shape and the tongue conversion was very well done.
Step 2: Preparing the Frame
So I took a sawzal and chopped up what was left of the old C20 bed and turned to getting the frame ready to go. The frame was in great shape, just a lot of surface rust and a bad bearing in one of the hubs. So I cleaned it up and gave it a barn quality primer and paint job.
Step 3: Starting the Bed
I wanted the trailer to be a deck over trailer, which means no fenders - that the bed covers the wheels. Didn't do a whole lot of measuring since I was not sure what I was going to do for wheels so I just started. I was able to use 4x4 posts for all of the crossmembers, bolted to all the stock mounts on the frame - 5 of them. The 4x4's all secured to the frame using galvanized carriage bolts.
I also added a 2x4 support over the axle which just sets on the frame and is not attached to anything but the decking. I was going for a deck that was around 6x9 (ultimately it wound up 6 x 8.5).
Then I attached 2x8 rails to the ends of all the 4x4's, spacing them so that they would be flush when a 5/4 deck board was set on top the 4x4's. This gave me the basic frame of the flatbed
Step 4: Deck It
Used 5/4 treated pine decking to deck it inside the picture frame of 2x8's. Wound up having to feed the center one through the table saw to make the last board fit. Everything is secured with stainless decking screws.
Step 5: Hand Mounting Some Tires
In order to get the tires to fit under the deck I bought some low profile tires with a pretty high load rating, and a pair of dually rims that would offset the tires to sit next to the frame and clear the side rail of the trailer. I'm not much for paying people to mount tires that I'm not going to balance so I took some scrap wood and built a little mounting jig.
The first step goes easy, screw the rim to the post through the lug holes and then soap up the inner bead, which you can pretty much just push on by hand at an angle. Then the outer bead gets soaped up and you use some prybars to get the bead on, while kneeling on the part of the tire that is already on. Takes about 5 minutes a tire once you know how to do it.
Step 6: Adding Some Hardware
Now that the basic flatbed was done, it was time to add the stake pockets and some tiedowns.
I used 3 pockets per side and 2 in the front. The rear gate would be captured by the sides.
Worst part of this was the wrist slamming from the huge hole saw require for the tiedowns, which are lag bolted to the crossmembers on one side and through bolted to the decking on the other.
The lights in the picture were not used, wound up with some oval shaped ones that worked better. They show up in one of the pictures of the tailgate later
Step 7: Stake Sides
Now I wanted to use this trailer to carry gravel and leaves, so I wanted some good solid sides. They are heavy! They are constructed from 2x4 stakes and the same 5/4" decking that is on the trailer deck. Used some slip steel corner brackets on the front corners to keep the sides and front together.
The back of the sides got a couple pieces of angle iron installed to create a slot for the tailgate to slide into.
You can see the lights just above the bumper. They are a surface mount LED light that only requires a hole for the wiring.
And that is about it.
The trailer is pretty heavy. There is about 600lbs of wood and hardware on top of what is likely 600-800 lbs of trailer frame and tires.
Used it quite a few times since it was built and I'm happy with it.