40k lb Bumper Hitch convert to Gooseneck

[BigcountryGA]

I have a motorhome i just purchased, its a 450HP Freightliner 32ft box rated to bumper tow 40k#, its not a toter bed, the 32 box is all a box. But i have multiple gooseneck trailers id like to tow with it.
I know the obvious reasons the gooseneck might hit the box but has anyone ever seen a hitch that someone has made for this? I am looking at building my own and extending it about 2ft off the back of the frame, My max weight is 21,000lbs and its rated to tow 40 so i assume i will be fine but i would really like some advice and pictures.

Thank you for the help.

 

[jasong-TC]

I thought about this, never found one that someone had done.
I thought about building a stinger like the wheel lift on a row truck.

 

[BigcountryGA]

I was thinking something like that. I have searched a lot but havent found one. I am sure i can build one, my only issue try to not hit the motorhome in tight turns.

My theory is if its rated to tow 40k lb the tongue weight will not be anymore than its rated for since ill never tow more than 21,000lbs.

If i end up doing this ill post a picture. Just hope someone has done this for some advice.

 

[samcrimm]

Here is a great set up for what your talking about!

 

[hot rod]

samcrimm- Good find on that hitch picture, I've never seen anything quite like that. Looks like a very elegant, and expensive, solution. Probably doesn't sound so bad vs. the total price when that guy is ordering a shiny new Powerhouse coach though.

Take a look through the trucks here:
Home | Heavy Haulers RV Resource Guide
those guys all haul 5th wheel campers with hdt's, and there are a few wild frame stretches on there to put the 5th wheel well behind a big box. Setting up for a gooseneck is essentially the same.

My concern on your project is hitch weight. Yes, your truck is rated to tow 40k trailer, but what hitch weight? Industry standard for a tag type trailer for proper weight distribution and handling is 10% of total trailer weight, but for a 5th wheel or gooseneck trailer that number is 20%. So even if for arguments sake you could hook your gooseneck right where the existing ball is, you may be over weight on the hitch weight. Then if you figure the additional leverage of putting that ball at least 4' farther back behind the truck (and farther from the fulcrum point of the rear axle) the worse that gets.

My suggestion is you need some solid advice from someone with better math/engineering skills on how all those lengths and weights workout before you start modifying anything. You'd really hate to find out the balance is all wrong at 75mph the first time you hit a bad curve or crosswind.

 

[Bob86ZZ4]

How about just using something like this?: Automated Safety Hitch, adds an axle to your pickup truck - welcome to mrtrailer.com

 

[Bob86ZZ4]

Or one of these?: TOW ALL dolly – System for hauling 5th wheel and goosenecks! | Ridingmode

 

[hot rod]

how about something like this:
The Automated Safety Hitch | Trailer Hitch | Gooseneck Horse Trailers | 5th Wheel RVs | Flatbed Goosenecks | Fifth Wheel
there used to be something similar called a tow-buddy, but I couldn't find anything current on it.

That dolly may be pricey, but when it comes time to move on it would presumably have some resale value, while a big ugly extended gooseneck hitch on the back of the coach may make it pretty hard to sell, not many buyers would want that.

 

[hot rod]

great minds think alike!

 

[Bob86ZZ4]

Here's a video of one:

 

[Bob86ZZ4]

There was a guy at the HDT rally a few years ago that used one of those dollys. He said it worked great. He had a bed on his truck for his Jeep.

 

[jasong-TC]

The problem is now you've introduced another pivot point.
Have you ever tried to back a hay wagon? Forget about it.

 

[Bob86ZZ4]

The one the guy at the HDT Rally had a electric motor in it that could back it up. I didn't look through those ones I linked to above so don't know if any of them has a motor.

 

[hot rod]

The one I linked to actually links to the truck at two points and does not pivot. The wheels on the dolly turn like the tag axles on a dump truck. So if anything it would actually back up better as the hitch would swing faster when you turn. more like a bumper hitch than a fifth wheel.

 

[samcrimm]

So my question is how do the trucker that pull doubles get hooked up in the yard? I have not figured this one out yet. HElp

Sam

The problem is now you've introduced another pivot point.
Have you ever tried to back a hay wagon? Forget about it.

 

[jasong-TC]

So my question is how do the trucker that pull doubles get hooked up in the yard? I have not figured this one out yet. HElp

Sam

You hook the dolly to the tractor, go get the second trailer, place that set in a good place.
Then you hook the first trailer, now back the front trailer so the hitch on the back of it hitches to the dolly.
It takes a lot with some room.

 

[samcrimm]

Thanks that makes sense!

Sam

You hook the dolly to the tractor, go get the second trailer, place that set in a good place.
Then you hook the first trailer, now back the front trailer so the hitch on the back of it hitches to the dolly.
It takes a lot with some room.

 

[Bottomland4x4]

My buddy in South Carolina built one for his motorhome, he has a 30 foot renegade on a Coronado chassis and pulls a 40 foot gooseneck hooked to the bumper hitch. It's over length but he said it pulls fine, I don't think he has had any issues with dot. He goes all over the east coast Vermont, Michigan to Florida and all in between.

 

[ChiefMechanicMark]

The idea is "doable" of making your own, however I agree the engineering needs to be considered.
Look at the back of a car hauler when the trailer is off. The 5th wheel is about six inches off the ground and is boxed tubing off the frame of the truck. That proves it can be done to haul a full trailer designed to carry four to five more cars on it, but it was engineered by someone a lot smarter than me.
The tow axle idea is great too, however one of the ones displayed is adding a pivot joint so backing just got a lot more complicated. The one that uses two anchor tow points is just making you vehicle overall length longer.
You definitely want to know tongue weights for any trailer to avoid overloading.

 

[Fireeater-TC]

Am I understanding the dolly info right....

I can tow more then my Jeep Grand Cherokee is designed for (7,500 lbs) by hooking up the dolly to my hitch.....

Jeep is 8 cylinder with tow package.