Want To Build a Dump Bed Trailer

[RoGrrr]

Fellow welders

I recently bought a dump bed that came off a 1 ton pickup. It is 6 feet wide and 8 feet long, inside dimensions, with a 42 inch high headache rack on the front. Full control tailgate. My plan is to build a trailer frame under it.

I’m from Dayton Ohio, which has a number of General Motors plants, and their local scrap yards are flourishing.

One yard in particular gets loads of truck frame rail “rejects” on a regular basis from the truck plant. These rails are 5/16 and 3/8 thick formed into U-Channels 8 or 10 inches wide and 3 inches deep, about 30 feet long. They have right and left sides. Both sides have a 3 inch dog-leg offset (call it a zig-zag. Uhhh, Not the ZZ that you smoke with) that runs about 4 feet, then 8 feet to the end. There are the usual holes for rivets all over them.

Anyway, I plan to get some of it and make/mount a frame on a couple of 7000 pound axles to carry the dump bed. I’ll be using a 12 volt hydraulic pump to run the cylinders to raise the bed. The scissors lift under the bed already has 2 2-inch single acting cylinders on it, simplifies what I have to build. The lift “slides” the bed up. It is not pinned to the bed and I think I will leave it that way. I’ve looked around the net and have a general idea what I’m going to build but I’m open to some ideas for my build. I’d like either some pics or drawings, hopefully with some dimensions for my project. I also plan to go to a rental place like NationsRent and look over their trailers.

I’ve been looking at SurplusCenter.com for pumps. Found a couple that look like what I need without extra valves or hoses and fittings.

I plan to have enough frame in front of the bed so I can mount a full size cross-bed tool box on it (also available from these scrap yards. Some real good alum diamond plate boxes show up for under $50). I might put the battery and pump in the box to protect from weather and pilferage.

I have looked at Gary Davis’ welding trailer posted either here or on the Hobart board a couple years ago and got some good ideas from it.

RoGrrr
Glenford Ohio

[Beefie]

Good luck with that project, sounds like it will be a fun challenge. I would look online at diffrent trailer manufacures and see if they list what they have for frame material , box tubing or c channel.

Good luck
Beefie

[HMW]

Repaired lots of dump trailers and 6"x 5/16" channel seems to be real common for frame rails. I guess you got a good deal on your material because most times its cheaper to buy one built already. I just bought a equipment trailer after pricing it out, labor and material. It was cheaper to buy one and so far its been great. I also built a dump trailer about 10 yrs ago and after 2-3 modifications it works fine. But not sure i'd do it again.

[RoGrrr]

Hi HMW

Well, I figured that for about a grand I will have my materials to build it. However, if my time were worth 25 cents an hour, I would make out all right on it.

However, they call this stuff hobby, so I will have fun with it and end up calculating my time out to be around ten cents an hour.

Lessee, The truck rails will cost under $150 each (I might be able to get by with one but I'll prolly have to buy two) and I already have the axles and tires. The bed cost me $400 and I need the pump - another $400.

Well, I guess I'll need a receiver and a jack and some lights.

Hmmmm

Well, by the time I get done, maybe I'll have well over TWO THOUSAND wrapped up in it.

Go back and re read my words - hobby Hobby HOBBY

Uhhh, good thing I'm not married. That being said, looks like I'll have to go down and draw me another draft beer. Shame the woman caint do that fuh me.

RoGrrr

Y'All have a good weekend

Pizza and beer for me RIGHT NOW !

Repaired lots of dump trailers and 6"x 5/16" channel seems to be real common for frame rails. I guess you got a good deal on your material because most times its cheaper to buy one built already. I just bought a equipment trailer after pricing it out, labor and material. It was cheaper to buy one and so far its been great. I also built a dump trailer about 10 yrs ago and after 2-3 modifications it works fine. But not sure i'd do it again.

[fun4now]

sounds like fun, be shore to post lots of pic's.

[c wagner]

I plan to have enough frame in front of the bed so I can mount a full size cross-bed tool box on it (also available from these scrap yards. Some real good alum diamond plate boxes show up for under $50). I might put the battery and pump in the box to protect from weather and pilferage.

Excellent idea, I built a battery box for a buddies trailer out of 1/8" Alum. checkerplate and also surprised him with a matching winch cover! Now I get to use the trailer when needed as long as it's available and the battery is always there!!!
Note: be sure to put a vent in the box if you do mount the battery in it, I just cut a hole and installed a pre-made round Alum. vent.

[RoGrrr]

Mr Wagner

Thanks for suggesting the vent. I will do that.

The box will be a full size cross bed box so I can put tools and chains and the like in it. Maybe even a chainsaw. I guess I would have to vent the battery directly out of the box so the acid fumes don't rust everything in the box. Guess I could use a sealed marine-type battery box inside the tool box and vent that.


What I'm looking for in the thread is some good data for building the frame. I have never built a trailer, let alone something as heavy as a dump trailer.

So if anyone has any ideas for me, let me know

Roger

Excellent idea, I built a battery box for a buddies trailer out of 1/8" Alum. checkerplate and also surprised him with a matching winch cover! Now I get to use the trailer when needed as long as it's available and the battery is always there!!!
Note: be sure to put a vent in the box if you do mount the battery in it, I just cut a hole and installed a pre-made round Alum. vent.

[Beefie]

If you have never built a trailer at all you might want to go to www.trailerplans.com or northern tool.com they both have plans that you can buy online. trailerplans .com is the least expensive of the two sights. Or you can look online and see if different trailer mfg's have a list of what material they use for there frames. There is some books out there that help you design a trailer, I have purchased "Trailers how to design & build" volume's 1 & 2 , written buy M.M.Smith. The books have a ton of good info in them.

Have you desided how much weight you plan to carry , or if you want a single or tandem axle. Those ? should be ansered first and then build a game plan from there.

Good luck and have fun with it
Beefie

[Rlrsk8r]

Beefie
Thanks for the leads on the books.

I checked out Smith's books from the library and found the veritable wealth of information you said.

There are things in the books that I hadn't thought about so it was well worth the effort to check them out.

I also checked out WELDING, FABRICATION and REPAIR by Frank Marlow. It's about 350 pages and I might just go out and buy it. Gives lots of tips that are great. I've been in the (hobby) shop and garage all my life and I still learned a lot from it.

Roger

If you have never built a trailer at all you might want to go to www.trailerplans.com or northern tool.com they both have plans that you can buy online. trailerplans .com is the least expensive of the two sights. Or you can look online and see if different trailer mfg's have a list of what material they use for there frames. There is some books out there that help you design a trailer, I have purchased "Trailers how to design & build" volume's 1 & 2 , written buy M.M.Smith. The books have a ton of good info in them.

<SNIP>
Beefie

[KBar]

RoGrr, if you have a local truck body shop, check them out as well as looking at other trailers. Check with your local road department to see where they get their trucks. These truck body shops build the dump beds for a living along with designing the hydraulic system. If they are like some in Pa, they will help you out with a smile and give you literature on how much pump you need, pressure, etc. There are so many options.

[HMW]

Sounds like a great project. The hardest part to me is to get the proportations right. It easy to build a dump box, or a frame and easy to make a tongue and install axles. Its VERY hard to decide where to put it all. On the dump trailer we built about 10 yrs ago, we have completely moved the cylinder positions [were mounted to far back] and have moved the axles twice now. The last modifications I made new hinges for the dump and replaced the rear cross member. Make sure you get enough tongue weight, we had an issue with that which I think is cured now by moving the axles toward the rear more. Also make the tongue tough, it has to pull and twist the rest of the junk. Also added a small cylinder on the front of the bed to help with the initall lift. It pushs straight up about a foot and runs with the larger cylinders. it helps alot. You need to have the cylinders back enough to make the dump go high enough but angled enough to be strong. We've dumped 5 tons of gravel many times and works well. good luck and have fun making it.

[DSW]

RoGrr Hi, I also have looked into building a damp trailer using an old 1ton dumpbody. The numbers don't really work if you are trying to save money ( Still haven't ruled it out from the fun/practice stand point). One thing that you may not be aware of. If you build the trailer with 2 axels that are larger than 5000 Lb you may have to get a CDL. In Pa if the GVW of the trailer if greater than 10000 Lb you must have a class A CDL. I think this applies nation wide(?) If you build the trailer with 2 7000 Lb axels DOT may require you to rate it at a GVW of 14000 Lb. In Pa you can not lower the weight of a existing trailer to below 10001 Lb if you don't replace the axels, and my under standing is that DOT will be determining your GVW of a built trailer based on the axels you choose. (in PA you will have to send in to the state documentation of all the parts used for the trailer, Reciepts for purchased parts axels, brakes, lights etc that are bought new, and VIN numbers and reciepts for anything coming from a used vehicle, ie. the 1 ton bed. (I ran into this problem with an old Uhaul box that I tried to build a small trailer for. Built the trailer but can't get them to register it because I don't have the original VIN for the doner truck.) This is so Pa can tell that you paid sales taxes on all parts, and that no stolen parts are used to build the trailer. You will also have to have brakes on any trailer heavier than 5000Lb. Electrics are great but you will probably need a controller in the truck.
By the way a class A CDL is the same as for a tractor trailer with all the same requirements, medical card etc. I also understand that it is a real pain to get a class A CDL in a light truck and trailer. They really want you generally to take the test in a truck greater than 26000 GVW with a trailer. I guess that this is to prevent guys from taking the test for big rigs in smaller trucks. DOT in my area have really been cracking down on dump trailers. (read easy revenue gathering) I know several guys that have sold their 5th wheel travel trailers rather than deal with the BS of getting a CDL.