Yet another gooseneck/fifth wheel adapter thread

[Tony_Berry]

There have been plenty of threads and discussions already, but I want to approach from a different angle as I didn't find my answer in the current threads...

http://www.rv.net/forum/index.cfm/fuseaction/thread/tid/29411839/
http://www.rv.net/forum/index.cfm/fuseaction/thread/tid/29443693/
http://www.rv.net/forum/index.cfm/fuseaction/thread/tid/29450264/
http://www.rv.net/forum/index.cfm/fuseaction/thread/tid/29507411/
http://www.rv.net/forum/index.cfm/fuseaction/thread/tid/29597336/
http://www.rv.net/forum/index.cfm/fuseaction/thread/tid/29693859/

And on and on.

I am debating an adapter such as this: https://www.ebay.com/itm/182895667420

My truck is a International 4400 Class 6 low profile. It has a tradesman bed and a gooseneck mount.



It has rear air suspension, but I wanted the extra cushioning of an air ride hitch/adapter. This will minimize the jolts to the trailer on the y-axis, but not necessarily the stress on the x-axis.

I would have to do some moderate fabrication to install a more standard fifth wheel... custom brackets, custom rails, etc. I have the tools and experience to do that, but it would be some work and I don't intend to pull a fifth wheel on a regular basis. In fact, I haven't really needed to pull one to date. I want the ability to help someone move a camper in a pinch... flood, fire, to/from the shop, in the event they don't have a means to do so. More of a option than something I'd use daily, weekly or even monthly.

Does anyone have verified stories of failures and how they failed? Poor quality adapter? Improper installation? Accident of tow vehicle? What factors (besides x-axis stress) may have contributed to the failure?

[Retired_JSO]

As you can see, answers galore, none of them having a failure. Physics will show, the force on the pin box will increase. Just like most ball mount hitch extenders reduce the capacity of the hitch by as much as 50%. On all the goose neck trailers i've ever seen, the overhang has a substantial "Gusset" between the vertical trailer frame and horizontal deck over frame.

[Tony_Berry]

VoodooMedicineMan wrote:
The other thing I changed was the solid pin to one that has movement fore and aft, I can't remember the name of it.

You changed the adapter or something on your camper? Is the adapter you have the same manufacturer/model as the one linked?

Nice horns

Thanks. One on each side and they are LOUD!

[VoodooMedicineM]

Nice horns

[VoodooMedicineM]

The other thing I changed was the solid pin to one that has movement fore and aft, I can't remember the name of it.

[VoodooMedicineM]

I tow a 38 ft Cedar Creek with it

[Tony_Berry]

VoodooMedicineMan wrote:
I have that adapter for four years and it works fine.

That's the response I was hoping for. Someone who actually uses one and for some length of time. Thanks for commenting.

The only problem is hooking up is harder.

My truck has a very high cab. I can see my ball quite clearly. In fact, in my case, I suspect it would be harder to hook up a fifth wheel because it is closer to the nose of the trailer and might be obscured unless I had an extended/offset pin.

[mkirsch]

NMDriver2 wrote:
The force needed to start the 5er moving or to stop it is the same regardless of the hitch. Having a gooseneck adapter does not magically increase the force required to move, stop, or turn the 5er. The force applied at the pin does not change.

I will not get into an argument about this but consider that your 5er is like a flag on a pole. The flag does not have more or less stress based on how long the pole it. The pole may have more or less stress based on length but the flag (pin of the 5er) does not.

You're looking at it upside-down.

The pin is the base of the flag pole. The TRUCK is the flag blowing in the wind (i.e. the force being applied to the flag pole).

So YES the force at the 5th wheel pin is greater with a gooseneck adapter (i.e. a longer flag pole).

[VoodooMedicineM]

I have that adapter for four years and it works fine.
The only problem is hooking up is harder.
I use a short CB antenna on a magnetic mount and place it on the cab side of the ball.

When the adapter touches the antenna I know I'm real close.

[valhalla360]

NMDriver2 wrote:
The force needed to start the 5er moving or to stop it is the same regardless of the hitch. Having a gooseneck adapter does not magically increase the force required to move, stop, or turn the 5er. The force applied at the pin does not change.

I will not get into an argument about this but consider that your 5er is like a flag on a pole. The flag does not have more or less stress based on how long the pole it. The pole may have more or less stress based on length but the flag (pin of the 5er) does not.

Draw us a free body diagram of the forces on the PIN Box with and without the extension as the truck starts to accelerate and then come back.

PS: I'm betting based on your comment, you don't know what a free body diagram is because it most certainly does change the forces.

[valhalla360]

fj12ryder wrote:
I don't think that occasional usage to move a 5th wheel would incur damage to the trailer. If a need-to-move arose I think you'd be fine.

Regular usage...possibly another story.

I suspect it's the opposite.

Pulling on a nice smooth road, you don't cause enough stress for anything to fail...

But hit that one big pothole or hump and there can be enough force to cause a stress crack. Once started, even the forces on the smooth road may be enough to cause it to grow.

So it's a kind of luck of the draw. One bump that applies force in just the right way sets off the failure.

It's hard to collect empirical evidence as there are a huge number of 5ers out there of different designs. Some are designed to handle the extra loads. Others are small enough that even though they weren't specifically designed for it, they are OK and others are marginal.

[sayoung]

The AUH has an extension tube for beds like yours.

[Mmwtdh]

Tony Berry wrote:

NMDriver2 wrote:
Having a gooseneck adapter does not magically increase the force required to move, stop, or turn the 5er. The force applied at the pin does not change.

Sure it does. More specifically, the direction of force, and where that excess is dissipated, changes. Simple leverage physics. Stretch your arm straight out with a bowling ball in your hand. You will exert a level of force on your wrist. Attach that bowling ball to a length of broomstick and hold it out. That force will be greatly exaggerated at your wrist.

I agree with this..... increasing the distance from the bottom of the pin box to the linear force connection will increase the torque on the box (significantly?).

[Tony_Berry]

NMDriver2 wrote:
Having a gooseneck adapter does not magically increase the force required to move, stop, or turn the 5er. The force applied at the pin does not change.

Sure it does. More specifically, the direction of force, and where that excess is dissipated, changes. Simple leverage physics. Stretch your arm straight out with a bowling ball in your hand. You will exert a level of force on your wrist. Attach that bowling ball to a length of broomstick and hold it out. That force will be greatly exaggerated at your wrist.

[Tony_Berry]

I was typing a response as you were...

sayoung wrote:
Is the ball a permeate mount or a turnover and is the bed flat or is ball in a recess trough ?

It is a permanent mount in a trough.

They do have an extension for the AUH if your ball is in the recess.

I guess that would be a consideration. I'll do some more research. The problem with the AU is the sheer amount of space it consumes whether being used or stored. It doesn't appear it would fit in one of my toolboxes. I don't want to necessarily give up safety for portability, but it is a factor.