Box Rocket Trailer Build

IMG_4850 by Adam Tolman, on Flickr

I've had this trailer for a few years now but thought it might be a useful addition here. First off this is nothing even close to the quality and detail of an Adventure trailer or some of the other professionally built trailers. I built this trailer purely out of necessity. At the time I built it, my wheeling vehicle was my FZJ80 Land Cruiser. I have a wife, 4 kids and a dog that all like to camping/wheeling so even though the cruiser will seat 8, with all of us in the truck there isn't that much room left for gear. A trailer seemed like the best option since I didn't want to add a lot of weight to a roofrack.
So my goals were simple.
1) Room for gear in the trailer
2) compact size for better maneuverability on trails
3) track width to match the Cruiser
4) Rugged enough to tow through the Rubicon
I wasn't worried about running power to the trailer for lots of things like a fridge or generator etc. I really just needed a place to put gear so we wouldn't be so cramped inside the truck. I drew up some basic plans and got all my measurements together and headed to the steel yard to pick up materials. At the same time I ordered a custom width axle with match lug pattern to match the width and lug pattern of the Cruiser.
The axle took just a couple days before it was ready. 3500# axle. No brakes. Also came with spring hangers and 3500# trailer springs for about $130.


For the frame I used 2.5"-3/16" wall box channel. I don't have a bunch of specialty tools, but I had borrowed a chop saw from a friend and a welder from another friend. And I had my 4.5" angle grinder and a bunch of grinding disks, flap disks and cuttoff wheels. I wanted to keep the dimensions similar to the M416 military 1/4ton trailers that have a 4x6' box. So I laid out my measurements on the garage floor and cut my frame to 4x6'.


When those were all squared up I tacked it together and put it up on my makeshift welding table and tacked in a couple crossmembers.


Once I had the main frame how I wanted it I welded it all up and cleaned up the welds with a flap disk.

 

Then it was onto the custruction of the box itself. I didn't feel a need to buid a box on frame design that would allow me to pull the box off the frame so it's all welded. For the frame of the box I used 1.5" thin wall box channel. the sides are 18" high. I got all the frame peices cut and tacked in place using my high-tech string method to get them aligned correctly






After the box frame was in place I added the top rail. For this I used 1x3" box channel. This would give me a wider top rail that would make it easier to stand on if necessary and a wide surface to seal against when I built a lid.

 

Now it was ready to get the axle hung. I flipped the box over and got all my measurements that positioned the axle just a few inches behind the centerline to provide a slight front weight bias for better tongue weight. Once in position I welded up the hangers, welded the perches to the axle and threw it all together.


I had an old set of stock rims/tires from a '92 pick up that I threw on the trailer just to make it easier to move around. It was starting to take shape.


I had a pair of Thule load bars and feet that I bought from my sister in law. She had them on her Honda Civic. I tweaked the clamps just a little and figured out they would work perfectly on the top rail of the box so I tried them out to make sure. Not a bad fit.

 

Now I needed a tailgate. I used some basic hinges I picked up at Lowes and built a frame using the same 1.5" box channel I used for the box frame.




I wanted to keep the latch system simple so I just welded some tabs and used a pin to keep the gate closed. It worked really well and keeps it all closed up nice and tight.

 

It was time for the tongue. I used the same 2.5" box channel I used for the main frame of the trailer. I chose the length of the tongue so that it was as short as possible to allow me to tow it easier on tight/technical trails. But it also needed to be long enough so that if I jackknifed the trailer it would not contact the truck.
I notched the front frame crossmember and welded in the tongue extending it back to the second crossmember.


Then added some traingulation and called it good.


At this point I had picked up a pair of matching FZJ80 wheels and a pair of used 285 75 R16 MTRs and put them on as well to get a better idea of the true ride height.


Sat pretty level behind the Cruiser


I had also purchased a Lock-n-Roll hitch


This was the best hitch option at the time for unrestricted movement with the exception of a full rotation pintle hitch. I prefer the tighter design of the Lock-n-Roll. If I were building another one now or needed to replace this hitch I would use a Max Coupler from Adventure trailer. It is a nice design that addresses the few drawback of the LNR.
I also had a square ubolt on hand that I cut down and welded to the tongue for a handle.

 

The end of the tongue needed to be reinforced so I added some material there.


Now that I had a rolling chassis, it was time for a test run around the neighborhood. Even though it was very light it towed very well and tracked straight.

 

I had found some safety chain loops at a local trailer supply place that looked like they would work great as tie down points on the inside of the trailer. They were shaped like this.


It was time to skin the trailer. I used a few sheets of 16ga sheet steel. I measured, marked and busted out the cutting wheels to start cutting the skins.










The skins were just stitch welded every few inches. later on I would use some 3M seam sealer on all the seams to keep things sealed up and rust free.
Here you can see the tie downs and I also welded in some captured nuts to the frame in case I ever wanted to use some plywood sides on the trailer for work around the house.

 

I had been debating how to handle the fenders. My options were to build my own and use a flat top fender design similar to the M416 or I could use some round style fenders from a trailer supply place that were the style of the civilian model M101 trailer. For the sake of cost and time I chose to use some 9" wide round fenders from the trailer supply place. I think they cost me $20. I cut about 6" off each end to make them flush with the bottom of the trailer.
I bolted them to the trailer sides and finished welding up the skins.








I wanted a small fender step so I used some of the 1x3" box channel I had left over from the top rail and welded it to the frame in front and behind the fenders with a small tab to bolt to the fender. This not only provided a step but really stiffened up the fenders.

 

Time for another test drive. threw on some cheap towing lights and cruised around town for a while. Even found a dirt pile to test the hitch.








At this point I was satisfied with what I had and figured I had met my goals. It was time to get this thing painted and finished up.

 

The only issue I still had was that the fenders I bought weren't quite wide enough to cover the tires. I didn't want the trailer to pick up gravel on the road and throw them into the cruiser. As luck would have it, early style Jeep CJ7 fender flares are the perfect radius for these fenders. I found some fenders flares locally and after the trailer had been sprayed with primer I bolted on the fender flares. I couldn't believe how perfectly they worked. And they really finished off the look of the fenders and covered the tires just enough.




Then it was time for paint. This was a budget build so there was no fancy paint on this project. I bought several cans of Rustoluem gloss white and sprayed 3-4 coats of primer and seam sealed all the joints on the whole trailer, then sprayed 4-5 coats of White paint. Turned out nice enough for me.

 

I wanted to protect the bed of the trailer but couldn't afford to have it professionally lined. So I chose to use Raptor liner. This stuff is great and IMO is easily the best quality of all the DIY spray on liners. The texture and finish is much better than other products and it's tough. I sprayed the entire tub and underside of the trailer and over the top rails. I also sprayed the underside of the fenders.




This thing was just about ready to use. I decided to just use the cheap magnetic towing lights I had. I secured the harness under the trailer and added some plug to the lights themselves. Since they are magnetic I can unplug the lights and pull them off the trailer so they don't get damaged on the trail.
I built a small coolor rack for the tongue that will also hold 3 fuel cans and used some Blitz can brackets for my water cans. Between the water cans I mounted a bracket for my CO2 tank. It still needs a lid but we got it out and started using it right way.

 

This trailer has worked out really great for my needs. Future plans are to finish up a lid for it. Add a water tank underneath and run some power back to it so I can put my fridge in the trailer if needed rather than always having it in the truck.
The trailer tows really well behind the cruiser, and even though the track width is just a little wider than the Tacoma it also tows really well behind the Tacoma too. It has made camping lots morecomfortable for me and my family.
Here's a few pics of us using it.














Just recently a friend gave me a set of 3 BFG KMs that came of his cruiser. These are 315 75 R16's. I swapped these onto the trailer with the extra as a spare. This size matches the Cruiser but is slightly bigger than the tires on the Tacoma but it still works great for both and I think the 35's look sweet.

 

thats a really nice trailer! good job!

 

Amazing work!

 

NIce work man!

 

Subbed. Looks great, I want one now.

 

you don't need much. Basic hand tools and a grinder/cutoffwheel and a welder. That's it.

 

Oh! Since I'm sure someone will ask..... I would have loved to just buy a Chaser from Adventure Trailers but there was no way I could afford a $15-20K price tag for a trailer. I figured I could do this one on the cheap.

Other than the cost of materials the biggest expenses on this thing were the wheels which cost me $100 and the Lock-n-Roll hitch which is about $200. I was fortunate to find tires for free. tires could be an additional expense for someone wanting to build a trailer.

In total I'm into this trailer about $1600. That was much easier to handle than thousands of dollars on a professionally built trailer. Like I said in the beginning this trailer is nowhere close to the quality or functionality of those high dollar trailers but it meets my needs and cost me much less.

 

imma tell you right now you sir could make alot of money building those trailers very nice work