Ive been jonesing for a box trailer for some time, but around here they always seem to go for a kings ramsom and seem to be built kind of flimsey. A couple of months ago I found a box at a local pnp for chump change. I dragged it home and have been looking for parts to turn it into a trailer. I have been looking for axles, but I want 102" overall width and a drop axle and I couldn't find any cheap. A buddy on the board made me an offer for axles, springs and tires that I couldn't refuse and even dropped them off. Now I guess its time to get off my ass and get dirty. Intended use will be for storing crap, renting it out at work, and for small contracting jobs. I also want it to be long enough to put my Scout in if the need ever arises.

My first decision I am agonizing over is if I want to extend the frame forward of the box. Reason being I would build a small box forward of the existing big box that would be a semi permanant home for a bobcat weld/gen, and a couple of gas powered air compressers. They would be ready to use at a minutes notice, and the box would be somewhat soundproofed. They would be out of the weather, out of the way, and there would be a couple of less heavy ass items to load in and out of the trailer every day.

2nd is the overall length. Currently the inside of the box is 14.5 ft. I really need 16 ft to feel that there is enough room for the Scout. Also because of the location of the door on the right side at its current length it would have a little too much tongue weight which would be much compounded if I have the gen and compressers mounted in front of the current box. Moving the door forward looks to be a huge hassle. It originally had a hyd lift gate and there is much structure back there that needs to be removed. Im thinking of removing the steel door frame at the rear and adding 2 to 4 ft using the same materials as the trailer is constructed of, and putting the door frame back on.

3rd is what to use for the new frame. Current construction has 2 C channels that are 6 inches deep and 30 inches apart. On top of that are stringers that are 3 inches deep and on 12 inch centers. I want the trailer to sit as low as possible, the current axles have a 2 inch drop and I plan on cutting the wheel wells large enough to accomidate a 4 inch dropped axle when I can round some up. From what I have noticed most big trailers around here have 6 inch frames. Because I already have the existing 6 inch rails I am in deep contemplation about using 4 or 5 inch C channels. I would notch the existing rails to clear the axles if I went with smaller channel for the preimeter frame. Im really vexed trying to decide on what to do about the frame.

Cant you put the axles where ever you need them to get the tongue weight right?

Whats the forward door location got to do with anything?

Would it be easier to cut the trailer box about one foot back from the front and add in the splice section there instead of messing with that rear door frame stuff.

The welder-gen at the front sounds cool, very handy. Looking fwd to your progress on this.

Cant you put the axles where ever you need them to get the tongue weight right?

Whats the forward door location got to do with anything?



i guess the door would be in the way for the wheelwell cut-outs ;)


IMHO build a tongue, stick the axles under it, sell it to a buddy and buy a longer box :p...there are many of them around...most of them are in the 24' range (MDT rentals like penske).
shortening a box is easy if you have a structural rivet gun but extending the aluminum extrusions will be a major pain in the arse and way too much labor and $
the top and bottom aluminum extrusions are also a major structural part and key to the integrity of the box; i personally would not try to extend them....

... forgot to add that i think your on the right track :)

nothing beats a quality commercial box . on my old tow rig i had a 26' box that i shortened to make room for a aluminum sleeper ;
http://www.v8rail.com/components/com_joomgallery/img_pictures/v8rail_1/misc_38/normal_dscf1812_20080914_1642719914.jpg

... forgot to add that i think your on the right track :)

nothing beats a quality commercial box . on my old tow rig i had a 26' box that i shortened to make room for a aluminum sleeper ;
http://www.v8rail.com/components/com_joomgallery/img_pictures/v8rail_1/misc_38/normal_dscf1812_20080914_1642719914.jpg I've always liked these type of setups... lot's of room and not too big!

Put it on a deckover trailer and you wont have to cut on the box for wheelwells and the side door wont matter

I've always liked these type of setups... lot's of room and not too big!

it was a great, reliable and safe rig ... i loved it and we made a lot of miles.
a set of new steer tires, regular oil change and fuel was the only expense we ever had with it.
it was a (ex penske lease fleet) IH 4900 with the high torque 466 inline 6, road ranger 6 speed, air brakes and air suspension class 7 (33klbs) downrated to class 6 (non cdl) 26klbs

... but after switching to a class 8 HDT i would highly recommend to skip the class 6/7 MDT`s; a class 8 may uses a little more fuel but to me the difference in safety, power and comfort is well worth it :)

oh...sorry for the highjack :shaking:


yes, i agree with superdave; deck-over would be easier ; no need to cut and re-enforce the structure

You need a longer box. You should immediately sell that one to me and find one that better suits your needs!

Deckover would be easier, but I want it to sit as low as possible. Thats why I am wrestling with what size to make the frame rails. If I go with 6 inch rails like most of the box trailers I see my floor height will be 3 inches higher than most because of the stringers on top of the rails.

Everything is for sale for the right price:)

just stumbled over some pics ;) :
http://www.truckpaper.com/images/Truck/fullsize/78054102.jpg
26' ex Penske truck box made into trailer
here is another one;
http://www.truckpaper.com/images/Truck/fullsize/78392574.jpg

For the "right" price I'll take it.

ChiScouter,

I'm planning a similar build as yours, except I'll be building a trailer version of Rooster Boosters toterhome with an 18 ft box and a 5-8 ft sleeper cab with a goal of maximizing multiple use. I like the idea of the "tool shed" in the front of the trailer. Even on my design, just an insulated, sound proofed generator box could power the sleeper and outlets in the box...

The frame is also where I debating what direction to take. My two options are 1) extend the current 6" channel frame under the box to the needed length and fabricate a tongue, or 2) utilize a camper frame longer than needed and shorten. Option one is stronger but taller than I'd like (I'm used to my dropped axle, dovetailed car deck trailer). Option 2 is a lighter frame with perimeter support to supplement the supports under the box.

I'm really leaning with option 2. Ground clearance is rather important when you're planning on loading anything from auto's and motorcycles, moving a household, or using it as a mobile workshop. I don't think the weight capacity of the 6" channel is needed mostly because its generally harder to load the really heavy stuff in a box (trucks get too big to load, and who wants to shovel 40 cubic yards of gravel in and out of a trailer?) Well within the 5-9 ton frame capacities of the trailer frames I have access to.

Hope to see more on this thread :) BTW, I have a a few picks of truck boxes converted to trailers if someone could post them for me. If anyone can, let me know and I'll email them to you ASAP :)

Hope to see more on this thread :) BTW, I have a a few picks of truck boxes converted to trailers if someone could post them for me. If anyone can, let me know and I'll email them to you ASAP :)

Red star, blah, blah, blah. :flipoff2:

email me at shawnkayak at yahoo dot com

Red star, blah, blah, blah. :flipoff2:

email me at shawnkayak at yahoo dot com


Sent- thanks :)

Hope to see more on this thread :) BTW, I have a a few picks of truck boxes converted to trailers if someone could post them for me. If anyone can, let me know and I'll email them to you ASAP :)

:grinpimp:

That last pic in the post above this one is sitting nice and low like I would like mine to be. It appears to only be using 4 inch channel. I wish I could see a pic of how it is built underneath. My plan is to keep the existing 6 inch rails and extend them until they tie into the tongue. Its just a guess, but im thinking that the original frame rails are removed on that trailer.



Right now I am searching around to try and get a good deal on c channel. For 5 inch I was quoted .88 per pound. I am not married to the idea of 5 inch, but I am a little scared or 4 inch.

How about rectangular tubing instead of channel??

I like your idea of extending the existing rails--just fishplate and brace the hell out of them. Would be stronger to attach 6" with good welds than to drop down to 4" or 5" for the tongue--and probably lighter overall.

What do you have for axles?

yes, i agree with MT4
i would use rectangular tubing and not channel.
i think the stock c channel spacers to raise the box over the stock truck frame are too narrow together for a trailer. i would cut them off and build a new, wider sub frame for the tongue/axles

if you build the trailer in the same style like the one in the last pic i think you could go with 4" tube. a commercial style box itself is very rigid . many semi trailers are actually completely frameless...
http://www.truckpaper.com/images/Truck/thumb/78374000.jpg http://www.truckpaper.com/images/Truck/thumb/78275500.jpg
... the side walls together with the aluminum extrusions carry and spread the weight (thats why you have to be careful to properly frame and re-enforce cut outs like wheel wells, doors and other openings)
IMHO i would feel comfortable with a full length 4" tube subframe/ "V" tongue and a additional center tube to the hitch that extends at least 4' under the box and is tied into at least 4 of the box H-beam stringers....
but i`m a kinda "overkill" guy :shaking:; i guess i would actually run the center tube all the way back to the first axle hanger/cross tube ...

Down here near houston those long penske boxes go for $800 -$1000. One thing I would reccomend is go with 2- 7000lb axles. They dont cost much more than the smaller ones and the trailer will be much safer and capable with them.

For now I have a pair of 5200lb 2 inch dropped axles with slipper springs. They are well used and came with a very decent set of goodyear marathons. Future plans are for 7000lb axles but for the price I couldn't pass these up to get the trailer built.

Im not familiar with slipper springs, so I need to do some research on the necessary hangers.

Right now I am on schedule to get this up and running for just under 1K total.