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4x9 custom trailer project

3038 Views 5 Replies 4 Participants Last post by  89YT12
New to the site, wanted to share my project from this weekend.

I've been doing the Uhaul rental trailer thing for many years now, finally decided it was time to get my own. The other day I found a used, homemade 4x9 trailer locally on craigslist for $200. What I am keeping; It's made from solid steel C beams, has a 2x10 pressure treated deck, A-frame welded on trailer tongue and basic tractor supply trailer lights. The axle is a 3600lb vehicle front axle that was originally equipped with drum brakes, however the brakes are presently not connected (maybe a future project). The suspension is supported by a stack of 5 springs and the wheel hub uses a standard 5x4.5" configuration. The seller and I agreed upon $200 for the trailer as it was. But that was really just the beginning of the expenses.

First, the wheels that came with the trailer were 15x7 passenger vehicle wheels/tires so these went right into the garbage. Picked up some new 15x6 wheels from tractor supply. They are load range C bias ply and rated for about 1800 lbs each. Second, the previous owner apparently was not a fan of safety chains, but that didn't fly for me. Drilled 1/2" holes into the frame and picked up a pair of Reese saftey chains. Third, rattle can sprayed and the entire frame with rust-converting paint (no primer needed says the can). What a difference a coat of paint makes. Fourth, re-wired the existing lights to use a 5 flat towing harness to match up with my 2006 Ford Explorer V8 tow vehicle. I had to convert to 5 flat on the truck to pull my boat trailer, so it's just easier for my to convert over the utility trailer too. Also, cleaned up all the wire routing and secured it properly. Finally, I removed the old plywood sides and re-enforced the plywood front.

Sorry, no before pictures, but here is how it looks now;









I'm into it for about $450 now, of which most of that is the two new wheels. These projects always have a habit of becoming more expensive then I anticipate, and I could probably buy a new 4x9 trailer for close to that price, but it wouldn't have the 3600 capacity of this trailer and it certainly wouldn't have 2x10 decking. Still debating how to mount up some fenders (if I even need them) and I also want to do something with the A frame area in front of the deck. Maybe a toolbox or just some mesh decking for extra hauling space.

Thanks,
Z
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That looks pretty good. :fing32:

A diamond plate or poly trailer tongue tool box would fix nicely up front and give you a bunch of lockable storage out of the weather for straps, binders, and chains.

Fenders wouldn't be a bad idea. They would keep some stuff off of your cargo and would help cut down anything thrown off of the tires from hitting other vehicles.

If it were mine, I would like to have some angle iron sides about 12 inches high or so.

I think you have done well for no more money that you have in it. The important part is that you are happy with it and it will do what you want it to do. Thanks for the pics! :fing32:
Second, the previous owner apparently was not a fan of safety chains, but that didn't fly for me. Drilled 1/2" holes into the frame and picked up a pair of Reese saftey chains.

Fourth, re-wired the existing lights to use a 5 flat towing harness to match up with my 2006 Ford Explorer V8 tow vehicle. I had to convert to 5 flat on the truck to pull my boat trailer, so it's just easier for my to convert over the utility trailer too. Also, cleaned up all the wire routing and secured it properly.
LOL, idiots w/o chains

i thought the 4 flat would plug into the 5 flat since its the same for the first four are the same, ground~parking lights~left~right, and of course the 5th on a 5 is back up ... just wondering

and i think DOT law says you have to have fenders just an FYI

Good work :thThumbsU, i spent more on my 4x8 than a new one, but it wouldnt of been of the same capacity or quality so i know where your coming from
welcome nice looking trailer u could also mount a spare tire laying down on a frame
Thanks for the replies !!

i thought the 4 flat would plug into the 5 flat since its the same for the first four are the same, ground~parking lights~left~right, and of course the 5th on a 5 is back up ... just wondering

Here are my experiences on 4 flat and 5 flat compatibility;

- If the vehicle has a 4 flat harness and the trailer is wired for 5 flat, you can connect the 5 flat trailer to the 4 flat vehicle without modification. The 5th pin on the trailer harness will rest outside of the 4 flat connector but the other pins will all seat properly. Obviously, in this case you aren't passing a reverse signal back to the trailer which makes backing up a loaded trailer with surge brakes impossible. If you need to back up in this scenario, you have to get out and replug the connectors together so that the 5th pin falls into the 1st pin on the vehicle. Then, when you turn on your lights, it will trip the reverse solenoid on the trailer.

- If the vehicle has a 5 flat harness and the trailer is wired for 4 flat, in most cases you won't be able to seat the connectors properly together. This is because the 4 flat connector usually has an edge after the 4th pin where-as the 5 flat connector has the edge after the 5th pin. This prevents the connectors from aligning properly. The times I have had this problem, w/o an adapter handy, I've had to cut out the wall edge on the 4 flat connector deep enough to allow all the pins to seat properly. This pretty much destroys the trailer connector, I really don't like doing it.

Here is an example of the type of connectors that are NOT compatible (reference the MALE trailer end only);



vs this style which usually is compatible;



Thanks.
oh none of my 4 flats have a "edge" so they will seat w/o a problem

i know backing a surge brake trailer w/o a back up lock out ....STINKS.....i been there with one that is like yours with the eletric lock out and not the eletric lock out, well i didnt have a 7 to 5 way so i used the 4 so i would have lights

keep up the good work:trink39:
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