Cheap Hitches, Big Loads, and Gravity

[mblaney]

Overloading aside - there are two things I would like to comment on:

The hitch (truck side) should have some kind of triangulation to prevent the sides from buckling. There would be significant side forces when turning or trailer sway and that will work the **** out of the side plates and fastening bolts. It would take very little to greatly increase the stiffness of the side plates.

I always modify my hitches (the part that slides into the receiver). I see lots of hitches that stick way the hell out the back of the vehicle for no reason. This creates a lever that works against the receiver frame and also increases the torque the trailer can exert on the tow vehicle. I find that most hitch adapters can be re-drilled to allow it be inserted further - sometimes as much as four inches. I shake my head when I see a minivan with a anti-sway hitch installed and the trailer ball is 16" from the rear bumper

Here are two pics of what I would consider to be poorly fitted hitch adapters.

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[franklin2]

I had a hitch like that one time on my truck. It had the bolt in center bar between the two rails. One day I loaded something and noticed the hitch move independent of the truck. Crawled under there and the horizontal bolts on the hitch were loose. I was glad I caught it and it scared the hell out of me. I replaced that hitch with a higher strength one later.

I just put a curt (15300 i think) on my 93. Nice class 5 - 2" receiver hitch. I was very impressed with it. I would highly recommend that as a replacement. I pull a big enclosed bumper pull trailer that can gross 14K by itself so I wanted a hitch that could take it.

Class 5 with a 2 inch receiver? See what i was talking about. Class 5 is a much heavier built hitch, but accepts the same hitch and ball as a class 3.

If you start modifying and beefing up these hitches, once you get it under there you start realizing what you are bolting to. The truck frame is barely thicker than sheetmetal.

 

[sjwelds]

you start realizing what you are bolting to. The truck frame is barely thicker than sheetmetal.

No doubt. As the old saying is, a chain is only as strong as it's weakest link....

 

[Ironman03R]

Are you picking up roll-off boxes with a pup trailer? I've never seen anyone pull something like that with a pickup.

 

[oregon96psd]

No doubt. As the old saying is, a chain is only as strong as it's weakest link....

Yep, there comes a point where the old pickups no longer cut it....even an f-super duty has a really light gvw, 13-15k lbs if I remember right? Frames, suspension, brakes, steering it all has a limit and the older you get, the weaker they were made.

 

[Clb]

Not for nothin....
Check out curt's new class 5 2" reciever hitch! You need to ask for it specificly as its not listed yet.
I am not in town to get the number now, if someone wants to pm me I can pull it from my file on the truck!
This thing is way over thier last 2" reciever in capacity.

 

[Clb]

I had a hitch like that one time on my truck. It had the bolt in center bar between the two rails. One day I loaded something and noticed the hitch move independent of the truck. Crawled under there and the horizontal bolts on the hitch were loose. I was glad I caught it and it scared the hell out of me. I replaced that hitch with a higher strength one later.

I just put a curt (15300 i think) on my 93. Nice class 5 - 2" receiver hitch. I was very impressed with it. I would highly recommend that as a replacement. I pull a big enclosed bumper pull trailer that can gross 14K by itself so I wanted a hitch that could take it.

Probably thiss^^^^^
As my reese distributer did not know about it!

 

[FORDF250HDXLT]

Not for nothin....
Check out curt's new class 5 2" reciever hitch! You need to ask for it specificly as its not listed yet.
I am not in town to get the number now, if someone wants to pm me I can pull it from my file on the truck!
This thing is way over thier last 2" reciever in capacity.

i see that.15300 supersedes the one i put on chip truck 15012

http://www.curtmfg.com/part/15300

http://www.curtmfg.com/part/15012

http://www.amazon.com/Curt-15300-Class-Trailer-Hitch/dp/B00AFVRF8Y

 

[franklin2]

It makes you wonder when the stud that holds the ball on will give way. I have never heard of that happening though. My truck came with a gooseneck setup in the bed also. The ball for that has a huge threaded stud on the bottom.

 

[Tim4]

It makes you wonder when the stud that holds the ball on will give way. I have never heard of that happening though. My truck came with a gooseneck setup in the bed also. The ball for that has a huge threaded stud on the bottom.

I bought my first new trailer in 1999. The first one that I owned with a 2 5/16" ball. The dealer was tightening the ball onto the head and snapped the threaded shank of the ball. He wasn't that big of a guy and the wrench was not that long. It must have been defective. Other than that, I've never seen or heard of ball problems. Pintle is my preference now though.

 

[OLDBULL8]

Was just pondering, what could have caused the hitch to do that. Being as the hitch side plates are bent like that.
I went back and looked at the safety chains in his second pic. They look to be way to short. When turning, if the chains are short, that will put a hugh strain on the hitch, could have pulled sideways and actually sheared the hitch to frame bolts. Safety chains should always have a loop in the just so they don't drag. Whatcha think. Thats my experience.

 

[Clb]

^^^^ good observation!
I will toss in,,,Trailer brakes nonopp ( the italian posta wire harness) over the tounge weight limit?
Dunno.

 

[jaluhn83]

Excess tongue weight. The side member you can see shows a classic buckling failure, which is indicative of a high vertically downward load on the ball, possibly combined with high forward force, ie a hard braking w/o good trailer brakes or frontal collision. However, force forward on the hitch (ie stopping) is primarily going to be simple shear on the frame to hitch bolts, hitch pin, ball, etc. The failure indicates compressive forces on the side rails of the hitch frame, as would be caused by the tongue weight - essentially the weight on the ball is rotating the hitch frame around the rearmost hitch to frame bolt, which puts the frame side rails in compression.

The symmetry of the bending makes me think that side forces, turning, chains, etc weren't an issue. Just pure and simple overloading the hitch frame.

Short safety chains binding would bend the receiver, hitch insert, trailer tongue, ball or chains - the forces exerted would be concentrated on the chains and framing that is actually binding. If all that was strong enough it could *potentially* cause damage to the rest of the hitch/frame, but that's unlikely given that the stress on the chains and ball and structure in the area would be much higher than that in the rest of the hitch. I'd expect the driver would fell it locking up as well and know something was wrong. Finally, even if that did happen, it would bend the hitch frame around a vertical axis (imagine what would happen if you welded the hitch to the ball and tried to make a turn)

I see no evidence of bolt or truck frame failure. The top of the side plate is still bolted on and there is no appearance of bending. I will try to post a picture of a bolt failure under high load I have....

From the failure and what I can see of the general construction of the hitch, I conclude that this is a simple case of undersized hitch - I'd expect the hitch was rated at somewhere around 500 lb tongue weight and it had 1500+lb on it.

Pictures are from a failure I had moving my backhoe last winter. Trailer weight was around 13k w/ ~2k tongue weight. Receiver was rated for it as best I know but am uncertain of exact specs. One of the rear hitch to frame nuts came loose and things got worse from there. Note that the damage is asymmetrical, the is no major deformation of the hitch frame, and that you can see the one bolt still in the frame with no damage to the corresponding hitch ear, and the other broken/cracked ears.

(No idea why the one pic is upside down.... forum software seems to insist it be that way.... )

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[jaluhn83]

Overloading aside - there are two things I would like to comment on:

The hitch (truck side) should have some kind of triangulation to prevent the sides from buckling. There would be significant side forces when turning or trailer sway and that will work the **** out of the side plates and fastening bolts. It would take very little to greatly increase the stiffness of the side plates.

I always modify my hitches (the part that slides into the receiver). I see lots of hitches that stick way the hell out the back of the vehicle for no reason. This creates a lever that works against the receiver frame and also increases the torque the trailer can exert on the tow vehicle. I find that most hitch adapters can be re-drilled to allow it be inserted further - sometimes as much as four inches. I shake my head when I see a minivan with a anti-sway hitch installed and the trailer ball is 16" from the rear bumper

With respect, I do not agree completely. The receiver and hitch should be engineered for sufficient strength for the load they're rated for when setup as designed - no need to add stuff to them, and could possibly make things worse if you're modifying things. If the hitch is a heat treated steel then you could actually weaken the hitch welding to it, and even if not there's stresses setup from welding. You're also going to make it more rigid which could cause other issues - The hitch frame may be designed with a certain amount of flex to allow it to evenly transfer load to the truck frame and the flex with the truck frame. If it's too rigid then it's going to going to concentrate load on the truck frame in certain spots.

Also, buckling of the hitch side frame as happened to the OP serves as a safety - in the event of overloading or stress failure (getting rear ended for ex), this provides a way for the hitch to fail without detaching from the truck. With the op, the hitch failed due to overload, but didn't break off instead it drug the trailer nose on the ground but kept it connected - if the frame was stronger then the next stronger thing would fail which might very well be the truck frame or the bolts carrying completely away resulting in the trailer taking off on it's own. I can't say for certain that a hitch is necessarily going to be specifically designed this way, but it makes sense and I'd expect a reasonably competent engineer to have considered it.

 

[jaluhn83]

To the OP - what was the actual weight of that load? If you're going to the dump I'd assume you'd have a weight ticket. I'd be real curious to see what it was and what the tongue weight was if known. Also curious how much the truck squatted - I'd think it'd be pretty close to the bump stops. May be worth calibrating a bit so you can measure the squat and get some idea of load / tongue weight - I do this when I'd heavy with my flatbed.

Folks have a real tendency to get uptight about overloaded trailer, and for a decent reason - way too many idiots doing it without knowing what they're doing. I'm not as quick to judge, but there's some truth in what they say, particularly if it's a common thing and commercial work. I've run over 20k a few times with my rig, but it's few and far between and done very very carefully.... And of course critical to make sure that all your gear is up to spec and capable as there's little room for error as we have both discovered the hard way.

Worth looking into limitations for license classes too - here in CA the limit for anything but a class a commercial license is a 10k trailer. Now, I bet that gets regularly violated, and isn't too likely to be an issue for an occasional recreational trip, but if you're commercial it's another ball game.