M101A bed removal

[Whitnel]

How hard is it to remove the bed of a M101A trailer? I have searched threads with no luck and looked for pictures but can't find a good picture of the underside of the trailer.

I am toying with the idea of making a dump trailer out of it. I have read that they are not made to dump as some advertise so trying to figure out how hard it would be to modify.

It looks like you could take the bed off make a frame on top of the existing trailer frame and hinge the two together at the back. Then the trailer would dump with a better angle. Of course a lifting device would have to be added, I might run a ram off of my tractor's hydraylics.

Thanks in advance for any help.

 

[KsM715]

Easy to remove. Basically is it just clamped on. There are bolts the run down both frame rails that have plates that clamp the frame to the box.

I'll go out and get some pics. Give me a few min and I'll be right back.

OK, I was a little off. Its a mixture of clamping and thru bolting. First along the front edge mine is thru bolted at the corners and on in the middle. Then moving down the frame towards the back there is one bracket mounted to the frame with a clamp on it. Then farther back the the bolt/clamp is inside the bracing that runs laterally (side to side) under the box.

Still easy to remove, and easily put a secondary square tube frame under the bed for support and hinge that at the back of the 101 frame.

 

[Whitnel]

Still easy to remove, and easily put a secondary square tube frame under the bed for support and hinge that at the back of the 101 frame.

Thanks,

That is what I needed. What do you think frame under the bed should be made out of? Square tubing or C channel? The frame looks to be C channel. I will need to price the metal out. Things can add up pretty quick so want to make sure this is the best way to go. The trailers are just really cheap for how strong they appear to be.

 

[blybrook]

Square tubing will give you the best lateral stability against failure while it is being dumped. Channel would work as well if it is large enough, but it is really your choice. You may need extra bracing with the channel that won't be needed with the square tube.

In my local area, it doesn't matter what the shape is, it'll be between $1.25 and $1.50 a pound depending on how much work the shop has to do to prep it (cuts, holes, etc...) Your local supplier may be lower, you would have to call them to find out.

As an example:

The smallest structural channel I would even start to recommend for a full 8' span rating is C4x4.5; 4" tall, 4.5 lb/ft. This will have a rating of 476 lb/ft for 8' total load with both ends simply supported. This member has an Ix of 3.65in^4 & a J of 0.0322 in^4.

A tube steel (AKA HSS) 3x3x1/4 is 8.81 lb / ft (over double the weight of the channel, but better torsional resistance). The beam tables do not cover HSS members as they do for Channels & W sections, but gives a flexural strength of 5.69 kip-ft for the member. This means that the moment you calculate must be below the above strength. This member has an Ix=Iy of 3.02in^4 and a J of 5.08 in^4

Based on the moment of inertia values, Ix / Iy, the channel is stronger. Based on the torsional stiffness, J, the tube steel is 157.7 times stronger.

I pulled the above values from the 13th edition steel manual, should you have a copy to reference.

I would recommend you sit down with someone who is familiar with steel design to determine what size members would be best for you to utilize before pricing. Don't let price be your only factor in design. Safety is first, not only your own, but everyone that may be nearby while you are utilizing the unit.

HTH, there are a couple different books out there on trailer design, some are better than others.

 

[Whitnel]

blybrook,
You just brought me back to my structural steel class. Been awhile since I messed with that stuff. Wish I remembered more of it. I still have my steel manual sitting in my bookshelf.

I think tubing is the way to go, should be easier to build with as well.

 

[Barrman]

The bed is easy to pick up with a few people or by yourself with an engine hoist.

 

[blybrook]

Whitnel,

Glad it helped. I deal with steel design on a daily basis and the current manual is always within reach at the office. I also have access to manuals dating back to 1901, should I deal with a renovation on a structure that has members no longer manufactured (happens more often than not).

The manual will help explain a lot of what you need to know. Use the beam tables to your advantage when designing; makes it so much easier.

Bill