56 Ford Stepside Trailer.... how to lighten and build

[corleykj]

Wants in a trailer: For some time I have been wanting a stepside box on a lightweight trailer frame with full size wheels. I don't do a lot of wheeling but like to camp and hunt on some rough logging roads in the mountains (and need to drive 60+mph pulling it). I want it less than 12' in length so I can park it behind our garage with alley access. I wanted something lightweight I could move by hand. I don't have money or time to build what I want yet...


Random purchase: Today I drove by a 56 ford truck bed trailer with a for sale sign on it, for a price I couldn't pass up. $150.
So I bought it on the spot realizing it didn't have everything I wanted, but might be a decent start. It has full size wheels (and a spare). It is 11' in length. It has a step side bed. I bought it from the family who bought the truck new in 1956.

But... it is heavy. I drive an fj40 and a 100. I can't maneuver it well by myself down my skinny driveway either.

Big Question: Can I remove frame material (cross members?) or other stuff to make it lighter? It would save me a ton of time to maneuver it by hand, and really make this trailer purchase a great time and money saver.

 

[Brimley]

Love it! Best weight reduction is change rear axle with diff for straight trailer axle..

 

[ntsqd]

More pics would help, but usually crossmembers are there for good reason.

 

[corleykj]

Thanks for the reply @ntsqd and @Brimley . There is a few cross members that I am not wanting to remove, just curious if that is a good place to remove weight. It is dark and I can't take pics now but will tomorrow. It does have the factory rear end with 5 lug wheels/hubs. It has two good wheels and a spare which I would like to keep and use. I would entertain replacing the axle with another axle or cutting out the rear diff and welding in a new tube/axle. The cool thing is the frame is straight through to the hitch (not dropped or raised like some model of truck bed trailers).

I guess another question is, can a 40 pull a trailer with the stock engine (1978 fj40 with factory 2f)? I would like to pull it into our mountains with a 2,500 ft elevation gain in 10 miles I think. It does ok without a trailer, but don't want to be unsafe going up or coming down.
Thanks again for any input.

 

[ntsqd]

Nearly anything will move it. Stopping it is another thing entirely. If you're going to be loaded coming back down I'd want brakes on the trailer. Should be able to buy a trailer axle with brakes in the same wheel bolt pattern as it has now. Unless that axle under it is a full-float design, AND you have the time & expertise to fangle adding electric brakes to it I really don't think further messing a differential is going to pay off.

 

[corleykj]

Stopping it is my concern. If I were to take to elk camp I would haul some water, fuel and a wall tent... maybe an elk on the way out, and that would be behind the 100. If I use it in the summer it will probably haul camping stuff and some mountain bikes and stuff behind the 40.

I am thinking of selling the fenders to make some money back and make some flat fenders like a military style trailer. If an electric brake axle is needed and I want to lighten the trailer up some, I may be better off trading someone for a small utility trailer and building a trailer from there. I just love the box on this thing with the ford tailgate that is original.

 

[cruiserpilot]

It seems like weight is your big issue. The F100 box is made of some of the thickest metal that they
ever used.. I used to own a '54. That thing has a cool factor, but I'd suggest you are 'weigh' better
ahead to just get an aluminum trailer. Save 100' of lbs right off the start. No dicking around. There are collectors out east that would pay you back with a bit extra I bet
for a complete rust free box for a collector '53-56 truck
My .02

 

[greentruck]

Good advice here.

Another way to reduce weight would be to scrap out the frame and truck axle, build new, and put the box on it. Depending on what the original capacity of the truck was, that's all massively overbuilt for trailer use, not just the axle, but that's a bigger project than you may want.

Without brakes, I'd say your 100 is probably OK with it when driven with care, but it would definitely be a handful behind the short wheel base and limited braking power of a 40. That might allow you to use in the near term, while putting off major work for a year or so.

 

[corleykj]

Great advice. I like the box, don't love the fenders. I have access to equipment to make a trailer or modify this existing trailer. Before I have it up I am seeing if someone is interested in it. I think to pull something safely behind the 40 it needs to be light weight and or have brakes. Keep the ideas coming!

 

[ntsqd]

Light AND with brakes is the best option.

There's a lot of info here, and though expensive there is one really good book on designing a trailer. A fair amount of what you'd get out of the book for designing a trailer can be had from this page: Design Library Scroll down to "Trailer Balance" & "Tongue Strength". Unfortunately the "Drawbar Strength" link is now dead.

 

[corleykj]

Thanks for the links to good info. I will do some reading. I priced an electric brake trailer axle. A person is currently interested in purchasing the trailer, but it will cost me about $700 for new parts to start building a small trailer.

 

[corleykj]

More pics of the trailer and condition.

 

[ntsqd]

Looks like some really heavy channel was used to build the tongue. I'd think if that if it were notched and bent frame rail that the outer corner wouldn't be so sharp.

 

[corleykj]

One thought is selling the fenders and tailgate to someone doing a restoration and looking for good parts, and recouping the money I spent on the trailer. Then drive it this winter in town behind the 100 and 40 before lightening it up and doing an electric brake axle. I love trailer builds and their uniqueness for each person using them.

 

[corleykj]

Well, this is what I have now. I sold the box to a person restoring their Ford F100. No I am debating disassembly, cleaning and packing and greasing the axle, and using it to build a trailer. I am also debating if I want to reuse the frame section in the rear, while remaking a nicer tongue section that looks better and is shorter. Either way my end goal is a light 4 x 6.5" open top box for a camping utility trailer. Anybody have much experience on rebuilding these axles? Or any experience building a trailer out of the rear frame of a truck bed, using truck springs and such instead of trailer specific stuff.

 

[myquestoyota]

Check out etrailer.com for a much lighter 3500 lb axle with brakes. You'd be surprised how inexpensive it is in the long run. And the weight savings would probably be substantial.

 

[ntsqd]

There is an advantage in the single tube portion of the tongue being long enough to allow 90° jack-knifing of the trailer w/o any of it running into your TR's rear bumper.

My own RoT for tongues is that 1/3 to 1/2 of the distance between the coupler and the axle is unloaded tongue. This makes them tow nice and are easier to back-up.

The slight bump in the top of the frame rails means that your box can't sit flat on top of the rails, it will need to have leveling spacers fore and aft of the bump.

The truck rear axle should be replaced. So should those shocks. That spring is obvious, suspect the other also has issues.

What I see is a Learning Experience.

 

[corleykj]

Check out etrailer.com for a much lighter 3500 lb axle with brakes. You'd be surprised how inexpensive it is in the long run. And the weight savings would probably be substantial.

I have some extra 40 wheels and was thinking of ordering an axle and hubs that match the pattern of the 40. I will price that and see. Thanks.

 

[corleykj]

There is an advantage in the single tube portion of the tongue being long enough to allow 90° jack-knifing of the trailer w/o any of it running into your TR's rear bumper.

My own RoT for tongues is that 1/3 to 1/2 of the distance between the coupler and the axle is unloaded tongue. This makes them tow nice and are easier to back-up.

The slight bump in the top of the frame rails means that your box can't sit flat on top of the rails, it will need to have leveling spacers fore and aft of the bump.

The truck rear axle should be replaced. So should those shocks. That spring is obvious, suspect the other also has issues.

What I see is a Learning Experience.

Thanks for the reply. Are you saying that everything on the trailer will need some attention? I won't be taking it on long trips, just to the mountains close by, or dump runs. One thought is building a box and dropping it on it (using spacer bars to make it level and to make up for the hump in the frame) and then if I wanted to save up and spend $400 on metal and axle and wheels then I could pull hte box off.

 

[ntsqd]

OK, my understanding of the use/need was off. For a 'junk' trailer I'd still change out the axle, shocks and springs, but build the box to unbolt and use box under-floor cross-members as the spacers.

Longer term I'd plan on moving the corner where the rails become the 'A' shape back closer to the front of the box while leaving the overall length the same. Bring the sides to the center tongue tube where enough center tube is left exposed for that 90° jack-knife option. I'd use a single piece of 2.5 X 2.5 X .25 wall tube for the main tongue tube. Run it from the shock cross-member (because there isn't a full depth cross-member to use further forward) or to a new cross-member placed at the front spring hangers up to 10"-12" short of where the coupler is now. Then slide a ~24" long piece of 2.0 X 2.0" X .25 wall into the 2.5 tube and rosette weld it into place leaving enough sticking out for the coupler to bolt to. The reasoning for this method is that you need to move the coupler load as far back into the frame as is reasonable and to increase the bending resistance of the frame at the front edge of the box. An analysis of any trailer frame will show that this area of the frame always has the highest bending load and needs the greatest Section Modulus (essentially bending stiffness for those not familiar with "engineering-speak").

By the time you've done all of this it might be better to have started from scratch on the frame.

Older leaf springs tend to be narrower than later model springs. Might measure that bent spring and see if you can find a replacement. Alternately a decent blacksmith or spring shop could make you a new one.