Buy a trailer (instead of a pickup truck)

[redpoint5]

Originally Posted by oil pan 4

A 5th wheel hitch in a minivan sounds like a recipe for disaster.
There is a very good reason that they only make class 1 hitches for the Aerostar.
This is usually what it looks like when a vehicle never intended to pull a 5th wheel is forced to do it.
Trailer fail pics - Page 7

I'm all about utilizing things in ways never intended, but even this is too extreme for me.

[freebeard]

I never said that it was a good idea, just that I wanted to goad someone into doing it.

Originally Posted by jamesqf

Isn't the point of a 5th wheel hitch to be able to have the hitch, and thus the weight, somewhat forward of the rear axle?

I think the idea is to have the pivot either [more or less] directly behind or above the rear axle center-line. I know with tractors, the hitch is below the center-line so the front wheels are pressed into the ground instead of lifted.

What I've learned is there are two types of above the axle hitches, gooseneck and 5th-wheel (with the notched plate).

[oil pan 4]

Some times you need a pickup truck.
Goose necks and 5th wheels are those times.

[freebeard]

Maybe a flatbed truck?

[skyking]

I bet that is fun!

[Fingie]

lucky 'murica, goosenecks were allowed just a couple years ago

[skyking]

They require safety chains, and 5th wheel hitches do not at least here in the US.
5th wheels are a little easier to get hitched as you drive them back in horizontally. Get the height right, and it will self correct a little left or right and "click".
Goosenecks you have to spot right over the ball and get out and jack down.

[jamesqf]

Originally Posted by freebeard

I know with tractors, the hitch is below the center-line so the front wheels are pressed into the ground instead of lifted.

I really don't see how the physics works for that. At least with the tractors I've driven, there really isn't much weight ON the hitch. Instead, it's a pulling force, horizontal instead of vertical. That would press the front wheels into the ground, but the geometry is at right angles to the loads on a typical automobile trailer.

[skyking]

the line of force is below the centerline of the rear axle, so that pulling force will impart a downforce on the front axle.
here is a story of the opposite effect.
When I was 15 we cleared a 23 acre orchard. We had a big cat take all the stumps out but left them in place so we could tow them down with the farm tractors. We had '52 silver jubilee 8N ford, and a little '72 mitsubishi diesel.
To get the stumps started in the loose dirt, we rigged to the top point of a 3 point hitch so it would tend to lift up a little as well as pull horizontally. This is WAY above the axle centerline.
I was towing a big stump down to the burn pile with the mitsubishi and I ran across the loose dirt where the dozer had filled a stump hole.
In an instant, the stump dug in and the front came up on that tractor. I was ejected off the back and rolled away to keep from getting crushed.
The tractor was sitting there in 5th gear wide open throttle, digging two holes. The same physics of where the forces were applied kept it from flipping clear over onto me. It was standing straight on it's tail
I cut the throttle and killed it, and we pulled down on the front end till it was upright.
Oh and I cleared out my underwear. :P

[jamesqf]

Originally Posted by skyking

the line of force is below the centerline of the rear axle, so that pulling force will impart a downforce on the front axle.

Sure. What I was getting at is that tractors and highway vehicles are quite different. With tractors, the load is almost all pull: the downwards tongue weight is usually tiny by comparison. With highway trailers, the tongue weight is proportionately larger than the pulling load (and except with 5th wheels) applied further behind the rear axle, thus the pictures of overloaded tow vehicles with their wheels in the air and rear bumper on the ground.