Why is my trailer suddenly so bouncy ?

When I was young and dumb I bought a green unit of 2x4x 96" about 3800lbs and put them in the bed of my 3/4 ton power wagon 6000lbs, then loaded two units of green 2x4x16ft about 9000lbs on a 20ft flatbed about 4000lbs hooked on and away I went with 22,800 gross.

My hitch tongue was 1/2" SS 4" drop hitch on a custom built 2" receiver with a 2"x1" ball.

When I had the guy set the 16ft'ers on, the truck squated a tad so I had him move'm back about 6".
I proceeded to the interstate and got on the ramp at 20mph and just as I hit 25mph the trailer took off towards the center guard rail accross 3 lanes. Lucky an experienced 18wheeler seen I was in trouble and gave me lots of room and there was no other traffic. Keep in mind I had no prewarning nor had no control of where I went as I was just along for the ride as the load was in control at this point. I was lucky enough to think to grab the trailer brakes as it was heading back towards the right shoulder of the road and got it slowed down and back under control. I took the next off ramp and went back to the sawmill yard and had him move the load forward 6".

I then headed for home 150 miles away. On the way I keep getting a slight thump and small viberation. I droped the trailer and seen that my 1/2x2-1/2"SS drop hitch has started to tear about 1/2" from one cornner. Gees, I prayed alot to GOD that night.

A new hitch and receiver was born the next day!

A couple days latter I have to go pick-up 4ton of feed and I'm still feeling that small viberation. While waiting for the mill I'm sit-in on another guys tailgate BS'ing and He says whats wrong with your truck tires? We go look and find that I had seperated the cords between the ribs on both rear truck tires. Them Coopers had 60k miles and still looked to have another 60k left on them. Being a full time 4wd I had to replace all four tires.

The trailer axle remains bent to this very day. Now I only use it for short slow trips for my farm on back roads. I never fixed the axle as I wanted a reminder of what not to do and that was 25yrs ago. It balds a tire about every two years or 600 miles.

I thought I'd share this with you so you might have something to think about as all that happened in about 6 seconds.

T_Bone

You ask what might be wrong with your truck or your trailer after pulling a 12,000 pound load (your estimate) with a half-ton pickup. You don't say what brand.

Had you considered that the problem might stem from the fact that you're pulling almost 50% more trailer than the absolute maximum that the truck is rated for? If we look at the specs for a Chevy half-ton, for exmaple, we find that the absolute maximum that it will pull is an 8200 pound trailer. That's with a weight-distributing hitch, sway bars and HD trailer suspension package. Ford and Dodge, about the same.

Please don't tell me that you're just hitching this thing up to a receiver hitch - at least let it be a gooseneck. Because if you are, then IMHO your actions change from being merely unwise to being criminally reckless. If it's a gooseneck, you've likley merely grossly overloaded the truck from a hitch weight standpoint. If it's a receiver hitch, you're very lucky that it didn't tear itself off the back of the truck.

Whatever the case, I doubt the problem is in the trailer. I'd be looking very hard at the truck.

Please tell me that I misunderstood what you wrote, and I'll be the first to apologize. But if it is as I describe, my question is not what is wrong with the trailer, or the truck, but what is wrong with you.

llater,

llamas

1. It was only for 3 miles at speeds no greater than 40 mph, trailer has excellent brakes, truck has excellent brake controller. Terrain is flat and rolling starts were easy and gentle. But the most important point is that it was only 3 miles and the terrian is absolutely flat.

2. It was a Toyota Tundra 8 cyl. which pulls with more gusto than my previous GMC 1 ton turbo diesel

3. Not a gooseneck, standard 2 5/16" hitch. Being a rolling load it was easy to fine tune the tongue weight to not overload the truck springs. This of course was not enough tongue weight to prevent fishtailing if I was going at highway speeds or down a steep hill, but I wasn't, so I knew it would be fine...and it was.

If you think the problem is with the truck, what, exactly might the problem be ? As previously stated, I considered that as well, and have closely examined the truck underside...all looks fine. I am still open to the possiblity of a broken shock or such. But it seems pretty unlikely all things considered.

That's why I suggest - since it was the truck that you overloaded by some 80%, then that's where you start looking for failures. The fact that you went slow and easy is all very well, but the fact remains that you asked it to do 80% more than the absolute maximum it was designed to do. I don't care how slow and easy you went, at some point, something's got to give. The reaction loads that you're injecting into the hitch, the frame and the suspension all increase directly in proportion to the mass you're pulling and as the square of the speed.

It doesn't matter how much power the truck has to pull the load - what matters is the strength it has to transmit that load to the trailer, and to resist the loads that the trailer sends back to it when braking or turning. A Chevy Cavalier would likely be able to get the trailer moving quite nicely on flat ground - does that make the Cavalier an acceptable tow vehicle?

I can't say what might be wrong but I would still look at the truck first. I suspect something in the alignment of frame, wheels and hitch. Or the hitch may be pointing up or down now, which would explain why you get strange reactions from the trailer but nothing when you're just using the truck. Or you may have moved the back axle rlative to the frame, either by slipping it or distorting the frame mounts.

I had a man come and dig me some footings this summer. He brought a midsize New Holland skidsteer with the backhoe attachment, about 14,000#, on a twin axle trailer much as you describe, pulling it with a Chevy 3500 dually. He was pulling it off a pintle hitch inserted into a receiver, much as you describe. The receiver was marked as being a 10,000# unit, aftermarket - Chevy doesn't rate this ride to pull 10,000 off any sort of straight receiver, only off a load-distributor, fifth wheel or gooseneck.

All was well until he had it loaded up to go. He put the truck in gear, pulled away smoothly and there was an All-Mighty Bang from the rear of the truck as the whole trailer rig sagged down until the jack hit the ground. One side of the receiver assembly had sheared off clean, the other side was starting to tear out as it tried to carry the entire load.

Took an hour of jacking and cribbing just to get it picked up enough to unhook the remains of the receiver from the pintle eye. Scary as all get-out, and he did the trailer no good at all getting the skidsteer off it with nothing to hold the front end down.

If'n he'd gotten a mile down the road with it, it would have killed someone when it let go, no way in the world you could keep something like that under control.

Despite what you say about this being "fine", I have to repeat my opinion that what you did was reckless in the extreme, certainly illegal, and shows a cavalier disregard for other road users which I find very difficult to stomach.

llater,

llamas

You're obviously aware of the limits of half-ton pickups - it's just that you decide that they don't apply to you. What can I say? Why do you suppose that Toyota defined the towing limit as they did? You think they might know a little more about the structural limitations of their design - than you do?

I have plenty of towing experience as well as semi-truck experience. Suffice it to say that if a semi-truck were stopped with a 71.4% overload, the driver's going to jail, and you would be crying for his blood. What exempts you from operating within the limits of your equipment?

Your accident-free experience does you credit, but that simply says you're a good driver. I don't care how good a driver you are if the equipment fails you due to gross, unpardonable overloading.

You towed 14,000# with a half-ton pickup? Your exuberant over-confidence in the margins of the truck is wonderful to behold. But, given that story, I stand behind my comment - reckless in the extreme. You haven't had a wreck yet? It's only a matter of time, if you consider it perfectly acceptable to overload in this way, and then scratch your head and wonder what you might have broken doing it.

Have a nice life. I just hope you don't drive in my neck of the woods.

llater,

llamas

Re the 14,000 lb towing incident, that was 20 years ago, and I'd never do it again...not because it was dangerous (here again, well within limits of the trailer, excellent brakes, gooseneck trailer, pickup had overload springs, etc.) but because it probably did damage the Jeeps rear end gears, and it was slow go on the hills. And there was that small possiblity of axle throwout I mentioned earlier.

Just to ease your mind, that incident and this latest one's are the only towing incidents in memory where I was officially overloaded. I'm not "bragging" about it and don't recommend it, but sometimes a person has got to do what ya got to do to put bread on the table.

I've since talked to the trailer dealer and the manufacturer on the phone, and they agree the culprit is most likely a trailer tire defect. Will let ya'll know the results of a "Dr. Tire" analysis soon.1

Tires, then wheels, then axles/bearings, then springs.

Steven

I've experienced your delima with a trailer of mine, and it turned out to be a sepration in the cords. I also experienced it with a Ford Thunderbird that I had bought with only 12,000 miles on the car, and when I would brake the steering wheel would shake mildly. I just attributed this to a slightly bent brake rotor. Boy was I wrong!! Turns out, when I went to have new tires put on at 38,000 miles, from "visible" wear, that when the tires were inspected after being taken off, one of the front tires was about ready to shread on me. It was coming apart inside. It was stupid of me to wait so long to just go in and have it checked. Anyway, after I put the new tires on, it doesn't shake at all anymore, who knows what damage I might have caused to other parts on the car for my waiting so long.

Anyway, just because anything you buy new, may be new, doesn't mean it won't have problems. There might have been problems with the batch in the factory.

Stephen

And.... what the others said. No guarantee but very simple to check.