Cargo Bed Dump Conversion Hinge Designs

[74M35A2]

I would put it together with the solid shaft so that it aligns and then cut it down to two pins, making two independent hinges. The outer part (center) about 4" and each end about 2"...same proportions as above.

I’m liking this more and more. So each hinge ends up being 8” wide? How wide is the frame rail top flange, and then you would center the hinge on that? Like the idea of position and secure them with a long rod connecting both first, then cut them each down to length, for alignment. Would like to be able to remove the hinge pin to remove the bed.

Since I want to raise the bed 2” additional anyway, these hinges may end up on blocks and I could then somehow use square U bolts to secure the hinge to the truck frame. Then removal and reinstall is much easier, no precision pins to line back up. Just U bolt on and off.

 

[big block 88]

I builted me a few of these out of them baby deuces.

I will try and get a pic of my hinges. I drew them in cad and had the plasma table cut them out of 3/8. The pin is a 1 piece 2" carbon round bar them i rose budded her till she glowed and quinched in oil. The one in my avatar has been going strong for 12 years now.

i prefer 1 piece pins all the way accross. The bed doesnt bind on slopes while dumping. But thats just me. I prefer a more rigid mount than 2 piece pins can provide imo. After building buckets for cat for years i just went with what a large excavator would have as a pin set up.

One thing i wish id done is used brass in the hinge plates.

 

[74M35A2]

All good info. Keep talking. Brass bushing? Brass pin? I don’t plan to haul much, just doing this for the novelty because I like hydraulics and to cut/weld steel, but wanting it to work with weight if needed.

Cool you have owned your truck that long. Pic looks great, must sleep inside. I have always been nervous of a scissor hoist due to an axle housing hitting it in full articulation when off road. I did buy my truck to off-road it. Have you ever checked that it is impossible for a diff housing to hit the hoist when the hoist is down and a diff housing is full up against the bump stops?

 

[big block 88]

Brass bushings i am starting to see the hardened pin gouging the hinge plates. But its used for gravel, woodchips, and anything else.

The truck is now owned by a good friend who we do work for. He was the one we did the ac install and painted the 923 for recently i posted in the 5 ton thread.

The truck is looking very rough nowadays. Its coming here in the spring for a full repaint.

But the dump hoist came out of a chevy topkick that was rolled. The truck has been loaded too heavy where the cylinder will stall, then its get clever time and make the load shift to the rear by reverse brake checks or 1 st gear clutch dumps. If you keep her under 10k it dumps just fine.

 

[Buffalobwana]

You got to go where your priority’s take you! I have the same issues, would probably spend days putting in a bigger heater instead of a new window...

We are of the same blood.

 

[Buffalobwana]

If you are putting in a winch, you know your fairlead is installed just below the tailgate, right at hinge height.

The lifted bed is the key that should give you the room you need. A full length hinge should fit and work just fine. Your winch can go farther up the frame, out of the way of the hydraulics, or tucked in tight between hydraulic cylinder and the hinge, and you can figure something out for fairlead placement that won’t interfere with the hinge. Probably cable under hinge.

Or ...

Consider some kind of roller installed across the beams if necessary to slightly alter the cables routing. The pressure on it would be minimal since the degree of change in the cables angle would be in the single digits.

You could even use another piece of the mechanical tubing installed on the hinge as a roller to relocate the cable routing slightly. I would install grease zerks outside the winch cables path to make sure that piece of mechanical tube rolls freely.

In this scenario the hinge acts as a fairlead altering the angle of the cable by only a few degrees. It’s a small load, one that you may not even need to employ after you get everything laid out.

I would lift the bed first and use 4x4 x 3/16 steel tubing. No sense in trying to reinvent the system with new parameters by installing a dump
bed, then lifting it. (Maybe you were going to do this and I didn’t read your post right).

Lift bed, put on your hinge (whether or not you plan on doing the dump project at that time or not) Then, install the winch or go ahead with hydraulics. I think there is plenty of room for each.

 

[74M35A2]

Correct. I already have a second 20k Garwood hydro winch, same as the front. So, plan is to remove the bed, set the winch in place at rear between the frame rails, add 2” thicker bed spacer wood, set bed back down, install rear hinges, then install the lift cylinders. Add 16.00 tires and plumb rear winch + dump cylinders later.

So, key point is how to do rear bed hinges with bed raised up 2” higher than it is now.

 

[Buffalobwana]

Does anyone use square steel tubing as their spacer? Even with 14.00’s rubbing can be an issue, and tire damage if you have not addressed the contact points.

The wood on it is a true 1” in height. I can see having one piece of wood, but, why not weld a 3” piece to the bed to rest on the 1” of wood?

Since a dump bed is always just a couple steps down on my list, I’m curious how and why others do what they do. I would want mine 4” taller if I’m doing serious off-roading with 16.00’s.

 

[Buffalobwana]

.
So, key point is how to do rear bed hinges with bed raised up 2” higher than it is now.

Easy.

If you insist on using 2” wood as a spacer, then this is the best way I can think of.

At the rear of your bed, where you want the hinge, you weld on a six to twelve inch piece of 2x4x1/4” piece of rectangular tubing in place of part of the wood. Weld your hinge to that. It would be as if you never lifted the bed at all.

 

[Buffalobwana]

I can draw you a picture if you want.

 

[74M35A2]

2” taller than the wood in there now. A 16.00 tire should be 2” taller across each radius than a 14.00 tire (4” total larger diameter). So, from axle center to top of tire should be 2” more than now. With this, I am assuming raise the bed 2” additional, and 16.00’s won’t rub the bed bottom in full articulation (?).

Yes, a square tube hinge pedestal should work I would think.

 

[Buffalobwana]

I get the 2” taller part on a 4” taller tire. What I’m getting at is that some say that 14.00’s rub and have had chunks go missing at full articulation. (Never go full articulation! ... Tropic Thunder reference).

So, raising the bed 2” puts You exactly where you started. Which was your goal. My point is, why not raise it another inch while you are at it to give you a bit more room?

You are are doing the work anyway, the additional cost is marginal, the 1” additional lift is not significantly detrimental in dumping a load (stop laughing). And you are getting some more insurance against tearing up a tire while out six-wheelin.

Just sayin.

 

[tobyS]

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[74M35A2]

Thanks.

tobyS, the top frame rail width is 3". If you are proposing each hinge 8" wide, is this then a plate 8" wide welded to the bed frame rail with the end tube pieces, and then a 4" wide plate attached to the truck frame, with the hinge center tube?

FYI, the stock wood height is 1", so I will just go with 3". 14's clear stock, so 16's should clear if +2". I want to retain stock tire-bed clearance, not make it look like it has a body lift kit on it.

The bed far overhangs the truck frame at the rear. If the hinge pin is at the rear of the truck frame, the bed won't be able to go straight up because it would hit the tow shackles unless I move those in. I'm sure whateve needs dumped is out by then anyway, no big deal.

 

[tobyS]

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[Buffalobwana]

I use a molybdenum grease or never-seize on the rotating surface. It's not like they are used all day and every day to have to put in brass or oil-lite bearing...(which I have several sizes in stock but seem to never use). On the 1 7/16 shaft with 1.50 inside there is plenty of room. How many loader buckets do you see with no bushing/bearing? I have replaced numerous ones on JD and Case payloaders, cutting them out and replacing with heavy wall tube with steel to steel and they work great (all day every day). Forget the bearing. A step above the HR or CR shaft would be a cylinder rod.

Sort of my line of thinking as well. I only suggested it for the winch cable roller. Why? It sounds like a real good idea for a winch roller to roll instead of slide on. It’s a very light load on it, nothing is forcing it to roll like a dump hinge pin. so a greased inside seemed to be a good idea.

I have only built one dump trailer and I used the hinges that came off the arms of a 20’ disc. They were sturdy, rarely used and never greased. Still working today.

 

[big block 88]

Theres one of the first i did. One piece hinge pin, and hardened spacer pad between the hinge plates. Later ones did not use this space as i had change hunge plate design to the frame to an offset.

My case equipment all have brass bushings... cat on the other hand uses some kind of hardened carbon steel and i cant remember off the top of my head what the name of it is.

I guess my point in the brass busing is, why not? It would be easy to insert and use set screws as a keeper or even make a retainer ring for it.

This first design was a bit rough but its seems to be the one holding up the best.

 

[big block 88]

When it was much younger.

As for lifting the bed to clear the winch just change the offset on the hinge plate and use 2x wood or square tube would be fine also maybe a bit louder when unladen.

 

[tobyS]

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[big block 88]

What did you hoist with? I have done a 101 with rear hinges and a winch to do the lifting. Winch was mounted on the tounge and a pedestal with pulley over it and a clevis welded low to the bed. Winch was dual function. There was a fairlead over the front edge to allow winching of the quad onto the trailer.