Worst. Drive. EVER!

MushCreek · February 12, 2012, 03:21:26 PM

Just finished a quick trip to haul stuff to our property in SC. In April, I'll be back at it full time. The trip, however, was awful! To preface: I took a small trailer, and built a plywood box on it, 6' tall, 7' wide, and 10' long, plus a couple feet of vee in the front in an attempt at aerodynamics. For some reason, it become very unstable much above 50 MPH, so we wound up driving over 600 miles on back roads. What is normally a 10 hour trip took 15.

What bothers me is I don't know why. I'd say the trailer weighed about 2500 or so loaded. New 3500 lb. axle, hubs, and tires, correctly inflated. The tongue was plenty heavy. The tow vehicle is a 7000 lb van with E rated tires at 65 psi. I've never had a trailer do that before, even badly balanced. I chickened out before I found out how bad the fishtailing might get. The only thing I can think of, other than some weird aerodynamic thing going on between the van and the trailer is that the trailer doesn't sit level- it leans back because the hitch is so high on the van. Still had plenty of tongue weight, but I wonder it the back tilt might do it? I left it in SC, as planned, and when I get back up there, I'm going to (carefully) try it with an adjustable height hitch to see if that corrects it. If not, I guess I'll cut the box off and have a bonfire!

I once had a Ford Bronco II, and set out on a trip after installing a hood-mounted bug shield, and a car-top carrier. It was horribly unstable with this combo, even though it was fine with either add-on by itself. Something about the combination made the rig squirrely. I hope that's not the case with my trailer- I have a lot of trips to make!

NM_Shooter · February 12, 2012, 06:21:11 PM

is the tongue perpendicular to the axle, or did the axle slip a bit?

Very strange. I think I'd give it a tow with another vehicle just to try.....

February 12, 2012, 07:44:48 PM

Loaded to heavy in the front? Axle out of alignment? To small of tires? Bias ply towed by radials will even kick your hindend once in a while.

peternap · February 12, 2012, 08:34:53 PM

Hmmmm....Mine does that if it's too light in the front!

FWIW, the first time I loaded my tractor on my heavy trailer (10,000lbs), I backed it on. All was fine to 35mph then a little fishtail. I adjusted the brake box figuring I had just put the brakes on.

At 55 it turned me every way but loose. I swung across both lanes a half dozen times until I locked the trailer wheels and got it straight. The next hundred miles were at 30mph

On the way back, I pulled it head on with the bucket on the tongue. That thing followed me like a puppy at 70mph.

They all have a mind of their own.

MountainDon · February 12, 2012, 08:52:32 PM

Had you towed this trailer with similar load weight and with the same tow vehicle, tires, hitch, etc. before?

Does the van have a particularly long rear overhang (behind the rear axle)? The longer the rear overhang of the tow vehicle the more pronounced the fishtailing and the easier it will wiggle. Ideal tow vehicles get the trailer hitch pivot as close as possible to the axle. That's one thing that makes a gooseneck / fifth wheel trailer a joy to haul. Even if the tail wags the truck doesn't. That's also one reason mobile home tow trucks have the hitch right up there at the rear tires.

With a 2500 lb total trailer weight the tongue weight should be a minimum of 250 lbs and perhaps as much as 300 to 375 lbs. Ten percent minimum of total weight on the hitch; 12 to 15% in needed at times, with 15% being the generally recommended maximum. How to those numbers compare to your definition of "plenty heavy"?

The tongue tilted up, not close to level, can also have a destabilizing effect. Trailer should sit as close to level as possible when loaded and hitched up. If not get a new dropped receiver for the ball.

The box should not have had that much effect. Maybe if there were severe crosswinds. Or possibly when meeting an 18 wheeler at speed on non-divided highways the turbulence could cause a momentary wiggle.

I had issues with sway many years ago with a B II. It was resolved with a dropped hitch. The B II is especially sensitive because of the short wheelbase. Ford had a number of lawsuits because of accidents related to the rear suspension in those. My neighbor died in one; widowed wife won a big lawsuit settlement.

On the other my lifted CJ5, with 33" tires, never had an problem towing... but it has virtually no overhang and the trailer was lifted too.

February 12, 2012, 11:25:13 PM

I used a very name brand enclosed car hauler to haul product for a business we had up from California. We would run 80 to 85 across Nevada, go with the traffic flow down to near LA. Ran like that loaded and empty.

Then I used the same car hauler to haul house hold goods to the Bartlesville, OK, Tulsa, OK area. It tried to kill us from Boise, Idaho to Oklahoma. I am not kidding. I was wanting to park it and walk home it was so white knuckled. I thought it was just loaded weird. Surely if we got rid of the load and headed home life would be good. To our horror it tried to kill us the whole way home as well. Only change in the truck was a new set of very name brand premium tires. Further anytime I used it after that with those tires same rodeo. My flat bed, stock trailers and fifth wheel still towed like a dream.

MountainDon · February 12, 2012, 11:50:52 PM

Another factor is tongue length, or rather more precisely the distance from tow vehicle rear axle to the axle of the trailer (or leading axle if there are more than one). The wider the trailer track the more they benefit from a longer tongue. I extended the tongue on my trailer by 18" over the way the shop made it. It is easier to drive, easier to see in the mirrors, bounces less it seems, and backs up easier. It can also be extended another 18" if I want. Remove two bolts, slide and rebolt.

I assume the axle is a proper trailer axle, designed for a trailer. They are designed with some camber to make them track better.

Apparently square corners are slightly more stable than rounded ones or a rounded nose. Not a big difference. Would have never thought that

Trailer stiffness is a factor too; the stiffer the better.

And as others mentioned, having the tongue exactly perpendicular to the axle is very important.

rick91351 · February 13, 2012, 12:39:05 AM

Some times a bad tow is not all that bad. There is a guy over at North Powder, Oregon that makes those tiny houses that you can pull. Some one stole one of his. I think it was right out of his factory lot if I remember right. They headed to toward Idaho with it on the freeway. They left it in little Ma and Pa truck stop parking just off I-84 at the little town of Durkee, Oregon. The builder reported it was recovered unharmed however never try and pull one of his over 50 MPH or it will scare you to death. Apparently who ever had stolen it had their hands so full they just dropped it and left it.

MushCreek · February 13, 2012, 06:11:51 AM

The trailer does have a rather short tongue. The van is standard length; not the real long extended jobs, so the hitch isn't that far from the axle. Trailer tires are 15", bias ply. I never had tried the trailer before in its current configuration. I did tow it as a flat bed, empty, but its quite a bit different now.

As for the tongue weight- I can only guess by the way it lowered the back of the van a little. It's well more than I can pick up, and I'm pretty strong. One of my get-rich-quick schemes is to invent a trailer jack with a built-in scale so you can actually weigh the tongue weight. I might someday build one for myself, at any rate.

First thing I'll try is getting the thing level- I think that might be the culprit. If that doesn't work, I might extend the tongue. If that doesn't help, it's for sale!

February 13, 2012, 09:25:22 AM

After it was unloaded how did it pull?

I can assume that the van has radials, my tire guys tells if one has radials they all have to be radials. So we do that. Yes, I assume he is just trying to sell me tires. And he is and does so it seems. $:-\$

When you get a chance, get underneath and check and see if the spring shackles are the same and have not moved or slid ahead or back. Are they wielded or bolted to the frame? Bolt or bolts missing or loose? Look to see if the axle is bent. Has it been hooked on something. Next jack and block it up and remove the tires. Measure from the point of the tongue to a like the spindle on the end of the axle. Is it the same. Spindle to the trailer front on each side. They should be square.

As I stated I know what it is like doing a 'road trip' with something like that. It is not fun!

MushCreek · February 16, 2012, 04:43:42 PM

Well- It'll have to wait until April. That's when I head back up to SC ( I left the trailer there.) It's still loaded, so the first thing I'll do is try it with a lower hitch, which will either eliminate the problem, or eliminate that for a solution (scientific method, and all that). I'll also take some measurements to make sure nothing is funny with the axle. If it's still squirrely, I'll remove some weight from the back, making the tongue heavier. If that doesn't help, well, it'll either be sold or the box will be removed and ceremoniously torched. I've towed it without the enclosure, and it was just fine. Don't need another open trailer, though. I'll try to remember to post the results when I get 'em. Thanks!

MushCreek · May 04, 2012, 06:14:07 AM

Well- an update. Turned out to be a couple things. Lowering the hitch height improved the ride about 75%; taking weight out of the back (making the tongue heavier) also helped. The trailer is so short that having the hitch too high essentially shifted the center of gravity back- not good. Thanks to all who participated!