Reese Goose Box installed on Toy Hauler (Mega Cab with 75 Gallon Aux Tank)

[SnoKing]

That was not your only point, but are you surprised that a company supports what they sell?

Many frames are Lippert too, so they are supporting both ends. There shouldn't be any surprise here, it's not smoke and mirrors physics it's basic warranty. It's uncommon for a company to warrant something they don't manufacture.

I'll take real physics over "smoke and mirrors" physics any day. There will be less strain across the board utilizing a goosebox than a gooseneck adapter, period. There would also be less stress even if the goosebox didn't have the air cushion.

Again you fail on the physics, without the air cushion the apparent level effect is the same, the fact that one gets there in a straight line and the other is L shaped makes no difference. The forces with the L shaped one is a straight line between the two contact points. You have to look at as a solid connect between the two contact points.

 

[Jim W]

A physics class on levers? Assume the pin box and goose neck adapter form a rigid single piece the force between the truck and the trailer is the dotted line. Just the same as the force of the goosebox between the truck and trailer. In the adapter case the truck and trailer do not know that the route between the two locations took a detour between the two points.

View attachment 127154

Where is your "FREE BODY DIAGRAM" ? That is what is needed to understand the forces at play on the frame of the 5er! There is never just a straight line component that puts the forces in play on any mechanical component. There is at a minimum of a horizontal force and a downward force being applied that needs to be considered than the vector angle will come in to play. Which should give you the "BENDING Moment" that the frame will see.

This all changes once the tow vehicle starts to make a turn and the force input changes as the angle changes in relation of the trailer.


That is why I would not tow any vehicle with a goose box type pin box. Now if the trailer is designed for a goose box such as a equipment trailer or a animal farm implement trailer than I would. But a 5er, I believe is not designed the same way and the connection point of the pin box is not deigned for these forces that are exerted by a goose box.

 

[AH64ID]

Again you fail on the physics, without the air cushion the apparent level effect is the same, the fact that one gets there in a straight line and the other is L shaped makes no difference. The forces with the L shaped one is a straight line between the two contact points. You have to look at as a solid connect between the two contact points.

On the contrary, you’re not looking at the application of the leverage between the two and associated forces. They are different, plain and simple.

If L shapes forces where the same there wouldn’t be a need for straight forces. But look at many different applications, from simple like how to brace a square box to more complex.

if you were to brace a traditional gooseneck adapter in the straight line distance it would in effect be the same as a goose box without an air cushion, but without that bracing you get the same forces applied differently. Without the bracing you also get different torquing on the king pin which then applies that force to the frame differently.

Static and dynamic application of forces are going to be vastly different, and that could be the confusion.

 

[bcbender]

There seems to be a whole lot of effort being exerted here to sway someone from using a Goosebox.... I have one, my dad has one,. Lippert says it wont void the warranty.. end of story........ Besides intuitively we all know if you have a frame warranty issue with Lippert it wouldn't matter what pin box you had; it would likely be an uphill battle either way....

If you don't like it, so be it, but don't sit here and tell someone whos asking and weighing their available options its no good because you "don't like it" as that is just wrong. Its different stroke for different folks... same for fuel systems... clutches,.... brakes.... etc... we like what we like. I will say that I've seen the bolt on pin box adapters that slip over the kingpin and I would be very skeptical of them ripping out the king pin plate alone before they did actual frame damage.

 

[SnoKing]

On the contrary, you’re not looking at the application of the leverage between the two and associated forces. They are different, plain and simple.

If L shapes forces where the same there wouldn’t be a need for straight forces. But look at many different applications, from simple like how to brace a square box to more complex.

if you were to brace a traditional gooseneck adapter in the straight line distance it would in effect be the same as a goose box without an air cushion, but without that bracing you get the same forces applied differently. Without the bracing you also get different torquing on the king pin which then applies that force to the frame differently.

Static and dynamic application of forces are going to be vastly different, and that could be the confusion.

Maybe you are missing the point that the goosebox pin box extends down lower in the truck bed to meet the gooseneck ball mounted in the truck just like the adapter does? The adapter becomes part of the OEM pin box and changes the connection point to a similar position as the goosebox.

Get a concrete block and clamp your 2' x 18" carpenters square to it so that it sticks out a given distance. Now take your fish scale and measure the force to lift the end of the block at the far end of the square. Now take something straight clamp and it to the block and create a lifting point at the same distance and height and lift with your fish scale. The force to lift should be the same.

 

[SnoKing]

There seems to be a whole lot of effort being exerted here to sway someone from using a Goosebox.... I have one, my dad has one,. Lippert says it wont void the warranty.. end of story........ Besides intuitively we all know if you have a frame warranty issue with Lippert it wouldn't matter what pin box you had; it would likely be an uphill battle either way....

If you don't like it, so be it, but don't sit here and tell someone whos asking and weighing their available options its no good because you "don't like it" as that is just wrong. Its different stroke for different folks... same for fuel systems... clutches,.... brakes.... etc... we like what we like. I will say that I've seen the bolt on pin box adapters that slip over the kingpin and I would be very skeptical of them ripping out the king pin plate alone before they did actual frame damage.

I never said anything bad about the goosebox. Only that Lippert supports it and not adapters that put similar forces into the 5th wheel frame. Maybe they feel that the air bladder absorbs enough of the vertical forces involved to save frame damage.

 

[AH64ID]

Maybe you are missing the point that the goosebox pin box extends down lower in the truck bed to meet the gooseneck ball mounted in the truck just like the adapter does? The adapter becomes part of the OEM pin box and changes the connection point to a similar position as the goosebox.

Get a concrete block and clamp your 2' x 18" carpenters square to it so that it sticks out a given distance. Now take your fish scale and measure the force to lift the end of the block at the far end of the square. Now take something straight clamp and it to the block and create a lifting point at the same distance and height and lift with your fish scale. The force to lift should be the same.

Nope, not missing it....

You're still only looking at it statically based on your example.

At this point it doesn't really matter thou.

 

[bcbender]

I never said anything bad about the goosebox. Only that Lippert supports it and not adapters

And that it the point for the guys who don't want to deal with the fifth wheel hitch and don't mind dropping the $1300+ labor to get the goosebox....

Kinematic ally, The air ride dampens the dynamic loading that helps propagate fatigue stress cracking (should it start) and in general the Goosebox is a much better built connection between the truck and camper than the 0.125 wall thick Chinese pin boxes most of the trailers come with OEM.. I think Wiredawg's 5th Airborne is the best Fifthwheel type and tech is what the goosebox was based on. As was mentioned earlier in this post, if someone wants to do a Freebody diagram of the loading I think you would find the total system is essentially the same. You must consider the hitch as part of the system since it is a key part of the "connection system" and the F (forward) force being equal and opposite to the F (rearward) force are separated by exactly the same distance (truck frame / camper). To leave it out is about the same as a Tesla driver saying the don't pollute since they leave the charger out........The difference between the two would be there are more lengths and angles involved, but each element has compliance and force is applied at the bottom of the fifth wheel hitch (or ball same place on B&W), and top mounting wings of the fifth wheel frame. There is likely a small difference in moment arm, but again have to consider the entire system. Maybe when I retire i'll get some paper out and calculate it.....

IMHO, there is more stress placed on these frames by driving 70mph on I-10 hitting all those bumps, and bridges, than the moment applied when starting / stopping. As has been said cracking is done cyclically over time by high frequency reversed loading. (or crappy welds)