Building a 5th wheel trailer to haul my tractor.

[dclynch]

I came a cross a deal on a trailer frame and decided to convert into a 5th wheel trailer to haul my equipment. It has a 29' deck and I want to shorten it up to 26' I was originally going to cut it off the front but all my buddies are telling me to cut it off the rear. My question is how far back should the axles be from the tongue of the 5th wheel or front of deck? I know most of my regular trailers the axles are 1' back from center ( if trailer is 20' long axles are 11' back from front of trailer) With a 5th wheel can I get away with the axles being a little further back?

 

[Ken45101]

Equipment haulers tend to have their axles back a bit. Gooseneck horse trailers tend to have their axles back even further. I mention that since it shows that the answer is "it varies".

HOWEVER,

1) a "5th wheel" equipment hauler? Until you get into the really heavy semi trailers, they tend to be goosenecks rather than 5th wheels.

2) Gooseneck equipment haulers are generally heavier structurally than bumper pull trailers. I doubt that you can just slap a gooseneck (or 5th wheel) front end onto a flatbed and not loose hauling capacity. The bed won't be strong enough to support the change. A right angle joint is weaker than a straight bed. You need heavier steel to support the joint.

Bottom line, if you don't really know what you are doing engineering wise, this sounds like a dangerous endeavor. Please don't take it out on the road!

 

[Renze]

What kind of tow vehicle (how much gooseneck pin weight will it take) what kind of trailer capacity, whats the current axle rating and towbar rating ?

 

[Shield Arc]

I've built a couple gooseneck adapters for flatbed trailers in the past. One for me, other for a buddy. They are a lot easier than one would think.

 

[SoGeorgia]

I've built a couple gooseneck adapters for flatbed trailers in the past. One for me, other for a buddy. They are a lot easier than one would think.

Holy crap you do excellent work brother!

 

[Shield Arc]

Thank you!
Here is the one I built for a buddy.

 

[SoGeorgia]

Thank you!
Here is the one I built for a buddy.

Will you be my buddy?

I've got an old flat bed that needs to be rebuilt.

 

[SoGeorgia]

I'm kidding.. Well.. Sorta..

 

[Shield Arc]

You mean you would trust me?
If so, bring it on up, I'm about 15-minutes north west of Tacoma Washington.

 

[SoGeorgia]

You mean you would trust me?
If so, bring it on up, I'm about 15-minutes north west of Tacoma Washington.

Yikes.. Next time you're in Georgia let me know!

 

[nc redneck]

First class work. Whatever you charged was probably not enough.

 

[Shield Arc]

First class work. Whatever you charged was probably not enough.

Thank you!

Charge?!:confused3:
Buddies don't charge buddies.

 

[Xfaxman]

I came a cross a deal on a trailer frame and decided to convert into a 5th wheel trailer to haul my equipment. It has a 29' deck and I want to shorten it up to 26' I was originally going to cut it off the front but all my buddies are telling me to cut it off the rear. My question is how far back should the axles be from the tongue of the 5th wheel or front of deck? I know most of my regular trailers the axles are 1' back from center ( if trailer is 20' long axles are 11' back from front of trailer) With a 5th wheel can I get away with the axles being a little further back?

What kind of trailer is the frame from? I would compare the size of the beams to commercial equipment trailers. If it was a mobile home it may require more strength. I have seen triangulation bracing added to frames to make them stronger.

How much weight will you be hauling?

There is a difference between 5th wheel and gooseneck.

5th wheel and hitch.


Gooseneck and hitch.


The axles are farther back on a gooseneck, because you want about 20-25% tongue weight on the ball.

 

[Chopperhed]

From what I understand, You want 80-90% the load centered over the axles. The trailer carries the weight, and the pull vehicle controls it.

Myself, I always center the biggest load over the axle/s and load smaller bits ahead of the axles to adjust hitch weight.

In this case, I would position the axles to anticipate the load. Or... build in a sliding axle setup, not uncommon on trailers hereabouts.

 

[CDN Farm Boy]

I've built a couple gooseneck adapters for flatbed trailers in the past. One for me, other for a buddy. They are a lot easier than one would think.

That's an interesting way to convert it, I'd never have thought of that and just cut the whole tongue off. Why did you do it that way and is designed to un-bolt to return to a bumper pull?

 

[hawkeye08]

I've built a couple gooseneck adapters for flatbed trailers in the past. One for me, other for a buddy. They are a lot easier than one would think.

Very nice, looks strong and uses the existing frame..

 

[Shield Arc]

That's an interesting way to convert it, I'd never have thought of that and just cut the whole tongue off. Why did you do it that way and is designed to un-bolt to return to a bumper pull?

My buddy removes his adapter all the time using his FEL on his tractor. I haven't removed mine yet.
There are four 1 1/4-inch A325 structural bolts, and two 1-inch bolts holding the adapters to the trailers.

 

[dclynch]

Shield Arc that is exactly the same style 5th wheel hitch I have that connects to the frame and trailer coupler. I figure the most weight I will ever haul on it is 7000 lbs it has 2 5000 lb axles. My tractor weighs about 3500 lbs I will haul that a 5' brush hog and a 5' rototiller and a quad.

 

[5picker]

I've built a couple gooseneck adapters for flatbed trailers in the past. One for me, other for a buddy. They are a lot easier than one would think.

That sir... is brilliant!
Very nice work too btw.
This idea will go into the memory bank.
My problem is... I'm at the age where something has to come out to put something in.
Hope whatever comes out isn't something I need next week!

 

[Xfaxman]

That sir... is brilliant!
Very nice work too btw.
This idea will go into the memory bank.
My problem is... I'm at the age where something has to come out to put something in.
Hope whatever comes out isn't something I need next week!

Yep, I have that problem too, that's why I have a projects file where I save pictures like Shield Arc's gooseneck adapters.

This is the latest someday roundtuit idea for storing the forks inside the shop: