P.J

See what I mean.........

PapaPerk

Gooseneck hitches (ball hitches) are used where you need the trailer to twist such as driving through ditches on farms.

Fifth wheel hitchs prevent the trailer rolling seperately from the truck. Basically its much more stable in turns. If the trailer trys to tip the truck must tip too. This is why semis use this set up (among other reasons).

Stresses are reduced on the hitch of the fifth wheel because its not reaching into the bottom of the bed. The hitch of the fifth wheel is flat with a pin sticking out the bottom. Just like a semi.

new2ctd

I have a Colibert with the adapter in my Ford and YES my trailer hated it with a passion. I didn't have it fixed because it's just used for the deer camp and I will probably never pull it again. If I do, it will be with my B&W companion.
Now my 5r is pretty old as it is and I'm telling you in about 2000 miles this adapter had caused all kinds of cracking, visible on the inside of the trailer mostly.

This is very very real folks. I wouldn't sell anyone my adapter for a grand.

1-2-3

The solution is simple. Ask the salesman of the gooseneck adapter for a WRITTEN gaurentee that your trailer will not be damaged from the use of his/her product, and if it is damaged, thier company will pay for the transportation and repar of your damaged trailer. See what you get.

DryCreek

I brought this issue up before, see thread:
https://www.dieseltruckresource.com/...d.php?t=117416

I am still a firm believer that if properly constructed, the gooseneck adapter will not place any unusual stresses on the frame that aren't already placed on it by an extended pin box.
The adapter shown in the photo posted in that thread have been on my camper since it was new in '99. It has seen many miles, and some of it offroad. No signs of frame damage - yet. Of course, my camper is only rated for a GVWR of 7,700#. I am not sure that the same results can be obtained with the larger 15K+ trailers that are already handicapped by an underrated frame right out of the factory door. About half of the "RigRats" in our area have the conversion, and they pull them regularly - over all kinds of terrain. All of the ones I have spoken to have had no problems, especially with the older (and more solidly built) models.

Dry Creek

P.J

Having the reciever directly vertical with where the kingpin is (would be), and full welded looks stout. It's the ones that are 8" ahead of the pin that look hokey to me.

Moral of the story really is that the manufacturers have an issue with it. If someone has an older unit and is confident they aren't doing to cause any unusual frame stress, go for it!

Bonshawman

Lots of good and accurate answers thus far. The RV's are not as built up frame wise as most goosenecks are. Plus, the gooseneck design, as stated previously, allows for more rough terrain flex and angulation, which for horse trailer, stock trailers, equipment trailers, seems important when leaving the pavement. I watch my 44' gooseneck enclosed RV/hauler rock back and forth on that single 2 5/16 ball and wince - but it seems to all hold together. The wind resistance on my goose is less, being only 9' from ground to top of trailer, than a big RV w/ slide outs would be. Everyone I know w/5th wheel RV's is aware that the convertors for gooseneck towing are not recommended by the manufacturers.
I hauled my 14,500# fire truck on my 6,500# (curb weight) 25' ten ton equipment hauler, and I grossed out just under my maximum combined vehicle weight ratings - just around 31,000# - but the rig handled it AND all my axle ratings were within limits as well. I am more comfortable with the goose than with former bumper pulls, but honestly I would be most comfortable with a fifth wheel set up (harken back to my tractor-trailer days) - ths issue of "giving up" the bed of the truck for me doesn't apply as I have a western hauler bed, so I pretty much have given up the whole back of the truck already ! The point is well taken on the fifth wheel plate support as well as the locking pin, and the lack of required safety chains - I look at the traditional goose set up with that long neck dropping down from the trailer frame to that ball......

FAY

The RV trailer frame for a given GVWR, both if used as a GN or 5th should be stronger than they are presently fabricated, but they do not need to be as strongly constructed as those for a heavier weight carrying trailer. I have pulled 12 ton of hay (payload) many times on a 24ft fifth wheel flat deck with a moveable lock-in place triple axle carriage. The trailer was fabricated by Maverick and it was well constructed. Nevertheless, I find heavy loads on a GN flat deck just as stable as those on a flat deck with a 5th wheel hitch. The only thing is the 5th wheel hitch is more likely to pull the tow vehicle over with the trailer in a roll over. The load of hay on my 5th flat deck was very high and it did feel unstable in corner even at slow speeds. When I had a fifth wheel hitch in the 1970s there were no goose neck hitches that I was aware of. I would never go back to a 5th wheel taking up the box, and I do think it is just a manufacturing marketing strategy to keep both types of hitches necessary for in bed hitches. Three types of hitches keeps the trailer industry in business.

displacedtexan

I think one thing that keeps the uitlity trailers, and cargo trailers mostly CN is that (around here at least) almost everyone has a GN ball, where as only the guys with campers have 5th wheels. (partially due to the fact that the GN ***** are cheap...)

XLR8R

I think the most glaring difference between 5th and GN is the pin load-bearing area... on well-built trailers, it's not an issue of strength. GN are more manueverable, although they certainly don't provide the same level of load PSI on the hitch as a 5th, so they can be expected to wear that much faster.