M101 dump trailer pivot

[quickfarms]

After 14 or so years the arms on the cast spring hangers finally cracked









The repair involved cutting off the broken stubs





Plates were fabricated to mount the heim joints to the frame





The repaired trailer back in action

 

[lexluther]

Well, Dang... half of me thinks 14 years is a long time, I should just convert mine and see how it goes without serious modification. The other half wonders if I could install a hydraulic ram for the dump and do it a little better. Thanks for posting the pics, it doesnt look like you have any trouble getting stuff out of the back due to dump angle...lol

Before we get too far in this thread we should acknowledge the dog dude and his perpetual wet blanket about how these trailers are not designed to dump...ok I get that part, now hopefully we can have a useful discussion about actual modifications...

 

[doghead]

Could you post a few pics of the new joints(close up)?

Thanks for the acknowledgment, lex dude. Reality should not dampen your perspective.

 

[Storm 51]

If you develop / design a hydraulic dumping system for these trailers, please post it. I'd be very interested in that modification, and I'm sure others on here would be as well.

Thanks,

Storm 51

 

[gimpyrobb]

Storm, you might be better off looking into a linear actuator for the dumping activity. Much less work to add one, just need to find a strong one. I picked up a 24v 500 pounder for about $50.

 

[quickfarms]

If you develop / design a hydraulic dumping system for these trailers, please post it. I'd be very interested in that modification, and I'm sure others on here would be as well.

Thanks,

Storm 51

I had thought about it years ago but I found that if the trailer is evenly loaded it is quite well balanced and dumps very easily. I use a 6 foot digging bar for leverage. I run it through one of the front shackles and put the tip between the spring and the front hanger by the pivot point.

Just remember to remove the tailgate before you dump

The picture is dumping about a 1 1/4 tons of stumps.

 

[gimpyrobb]

Did you ever put a flexible brake line on the trailer or did you not bother with it? I figured you removed the wire harness clips with it tilted that much.

 

[MarcusOReallyus]

I had thought about it years ago but I found that if the trailer is evenly loaded it is quite well balanced and dumps very easily. I use a 6 foot digging bar for leverage.

I just unhook and tip mine. Works fine. If I need the help, that's why I have my farm jack permanently bolted to the side.

Gotta get some wing nuts for that one of these days, but for now, a crescent wrench works fine.

 

[lexluther]

Picked up a load handler today, $35 at harbor freight. going to try and fit that on the trailer and see if its a good compromise. Also made a trip to Tractor supply to look at hydraulics and heim joints. They had lift arm ends, but no heim joints.

The wet blanket only dampens my perspective of the usefulness of this site, when you search for some info, and every thread on the topic has the same wet blanket killing the thread, it gets old.

The hydraulics idea seems nice, but I wonder if the joint were improved if it might be good enough as Quickfarms seems to have concluded. although there is so much room under there, it would surely work. Even if it cost another $1500, it sure is much cheaper than buying a new dump trailer.

Quickfarms, do you think you could post a close up of the heim joint attachment, and your bracket?

 

[Fredo Corleone]

Did you ever put a flexible brake line on the trailer or did you not bother with it? I figured you removed the wire harness clips with it tilted that much.

The trailer looks like a M101A1 no surge brakes.

 

[gimpyrobb]

The trailer looks like a M101A1 no surge brakes.

Ahhh! I put an A2 surge brake on my M101 trailer, I keep forgetting other folks don't have that!

 

[quickfarms]

The trailer is an old A1 and does not have surge brakes.

After I installed the heim joints I was surprised at how easy it was to dump.

The trailer pivots on the tires so you are only lifting a small portion of the load. The portion behind the axle acts as a counter weight for most of weight in front of the axle.

On a regular dump trailer the pivot point is near the rear of the trailer and the hydraulics have to lift most of the load and bed. I did consider converting the M101A1 to a regular dump trailer. The M101A1 frame is very weak compared to the M101A3 frame but the pivot point clunk be installed just behind the rear spring hanger. The second issue I had is the bed would need a sub frame.

The truth is the trailer works well as it is.

If I had to build a replacement I would use a M101A3 trailer, due to the smaller wheel wells. It would probably have A2 tires under it also.

Lift arm ends are the tractor ball ends. CAT 0 have a 5/8" hole in them, which if memory serves me is the bolt diameter on the trailer. The issue with the CAT 0 ends is I have not found them with the tabs welded on but now I have found a place that can cut the parts for me so that may be an option if I have issues with the heim joints.

 

[MarcusOReallyus]

The wet blanket only dampens my perspective of the usefulness of this site, when you search for some info, and every thread on the topic has the same wet blanket killing the thread, it gets old.

Agreed..... but.....

It's not old to the many newbies who come here looking for info, and have heard the myth that these trailers are MADE to dump, and don't know the risk involved.

I think it's a needed warning for that reason.

 

[quickfarms]

This is the front pin modification



This is the tailgate pin modification











Some close up pictures of the pivot modification.

 

[jesusgatos]

Not trying to be a jerk, but the way those eyelets allow the pins to move around a bit, and the way those heim-joint are oriented - that's a bad combo. Looks unsafe. Would be much better/stronger if you made some simple brackets to re-orient the heim-joints so they'd be inline with the trailer tongue. Again, only trying to be helpful.

 

[lexluther]

Thanks for the Update! I think that I can manage that mod.

Since my last post, I decided to try the knock off brand of the "load handler", the magic carpet thing that you use to crank out you load. I must say I am amazed how well it works, for me it may negate the need for the mod. I can crank out 1 yard of wet road base in 60 seconds. The knock off was $45 at the local Harbor Freight, and with my 25% off coupon, I was out the door for about $35. As an aside, shipping from HF website seemed crazy low for such a bulky heavy item. The name brand item is $190 with shipping. I would highly recommend trying this thing, it really is amazing, I think I have been unloading trucks wrong my whole life. In fact, I am totally stunned that they dont sell these things at the landscape materials yard, they could make a killing.

The only modification I had to make to the trailer was to add a length of chain so the tailgate would hold at flush with the bed of the trailer. There is a strap that is meant to attach to your truck bumper to keep the tailgate from lifting while you crank. The one negative of using the unloader on the trailer vs the truck bed is that there is no bumper to attach that strap to. I simply held the tail gate down until the load shifted back and put some weight onto the tailgate.

It would work even better if you had a slick bed, I am going to keep an eye out for a rigid plastic bedliner that I can cut up to fit the bed of the trailer, but it worked fine on both my truck that has a spray in bed liner (but only half a yard) and the trailers CARC painted bed. If you had someone drive while you crank, you could spread material easily, or park a wheel barrow at the tailgate and just crank it in...as i said, i have been unloading trucks wrong my whole life.

Finally there is a thread that shows the mod, the fix, and an alternative to the mod. I would highly recommend anyone thinking of doing the dump mod to try the load handlers oriental cousin, at $45 you don't have much to loose, and you can still come back to this thread for some great ideas to make the actual dump mod should you not be satisfied with the magic carpet...

Lex

 

[quickfarms]

Not trying to be a jerk, but the way those eyelets allow the pins to move around a bit, and the way those heim-joint are oriented - that's a bad combo. Looks unsafe. Would be much better/stronger if you made some simple brackets to re-orient the heim-joints so they'd be inline with the trailer tongue. Again, only trying to be helpful.

The heim joints are not the weakest link structurally and they are rated for 9,800 lbs each.

If the heim joint does start to bend the eyes at the front if the trailer would be on metal to metal contact before catastrophic failure happened.

The eyelets are forged lifting eyes. They are not the weak bent style. They only allow the pins to move about an 3/16 of an inch.

During normal towing the heim joints are not subject to a lot of stress unless you do something that could bend the pintle riser.

The joints are orientated that way so that they are in compression when they see there maximum load which is during power dumping when I back the truck into the trailer and raise the bed so it is near vertical.

If in the future we notice any indication that the heim joints are moving we can replace them with the high strength, 17,900 lbs to 23,500 lbs rated, ones or convert it to CAT 0 tractor ball ends mounted in 3/8 or 1/2 steel mounts.

 

[jesusgatos]

Wouldn't worry about the eyelets failing, as much as the pins bending. That's not an ideal setup, with the slop between the eyelet and the pin and the spaces between the eyelets and the tabs. If the heim-joints failed it would put massive bending loads on those pins (instead of being in shear, where fasteners are strongest), and wouldn't expect them to hold up well to that kind of stress. If by power-dumping you mean applying the trailer brakes and backing up, then that's no different than the acceleration and braking forces I'm concerned about, and that whole setup would be a lot better/stronger if you re-oriented the heim-joints as suggested. Replacing that eyelet with two tabs the closer to the diameter of that pin, and closer to the tab on the frame would be another big improvement. Not attacking you or anything, it's just that as is, it's dangerous/unsafe.

 

[quickfarms]

I understand your concern but the calculations prove otherwise.

The class III receiver trailer hitch has a rated capacity of 8,000 lbs. If you perform the calculations for the strength of the receiver hitch tube each side of the tube can take about 4,700 lbs for a total of 9,400 lbs.

As far as a failure of one heim joint bending the hitch pin on the front if the trailer, this is not an issue if the trailer is properly loaded due to the fact that the center of the bed is just forward of the axle. This happened when when the first tab broke and there was no noticeable change in how the trailer sat or towed. When the second tab broke dumping the trailer the front of the trailer dropped a little. If this happened on the freeway the ends of the tongue might have been ground down a bit on the pavement but the trailer would have still been attached to the tow vehicle and controllable.

The ends of the tongue are significantly weaker than the heim joints and have a strength of about 2,350 lbs each.

The way the tongue is attached to the trailer provides vertical strength but minimal horizontal strength due to their design.

 

[lexluther]

Seems like sufficient capicity in the joints for a trailer with a capacity of @half the rating of each joint. QF - How long did you go on the originals before it broke, and how long have you been using the heim joint?