Dumping a frameless dump trailer

[Countrycuz666]

I have a dispute with the company I work with regarding placement of the 5th wheel pulling frameless dumps.
I have been driving frameless dumps since 2006 hauling demolition debris and concrete.
My boss buys all of his trucks at Auctions and saves a lot of money in doing so but some of these trucks used to be fuel haulers and the company had put the 5th wheel 8inches forward of the center axle line. It is from my experience that when running in land fills in mud and slick areas the trucks are more prone to spin the tires and get stuck more often than if the kingpin was centered between the drive tires to balance the weight. His argument is that because these trucks have air ride suspension it makes no difference. I have personally been on leval ground in a field with wet grass and an empty trailer and back tires would just spin on the grass and not even dig a hole. the power divider would not even help and I would have to get the track hoe to push me. I am looking for opinions on this matter from people who have frameless dumps and where they have their kingpin set. thanks

 

[mitch504]

I generally keep a sliding fifth wheel one or two notches forward of the center of the suspension. It doesn't really affect balance between the rear axles. Where it makes a difference is on the balance between the steer and drives. If you have it too far back it causes several problems. It will let your front wheels slide on dirt or gravel when you try to turn, and it will wear out those expensive front tires quickly, because most front axles and suspension is designed to be properly aligned when loaded to a certain weight (usually 12,000 lbs).

 

[Countrycuz666]

1 or two inches sounds ok but what I am dealing with is perhaps ten inches forward of the center line. Two more inches and it would be over the second axle.
my rear drive tires are prone to spinning if there is any wet grass or mud since most of the weight is on the front drive axle. Does having air ride suspension make a difference instead of springs on the truck? I just want to move the fifth wheel back to put some weight on the back axle that does the work but it wont do the work if there is no traction to the ground.

 

[Countrycuz666]

I forgot to ask.. are you pulling a frameless dump trailer? do you go to land fills?

 

[mitch504]

1 or 2 notches on a sliding fifthwheel, not inches. about 6-8 inches.

Used to use frameless trailers, haven't since 2010. Still go to landfills occasionally, mostly deliver into farm fields with frame trailers now. I used to have a bunch of tractors, pulling mostly dump, did a bunch of demolition in Myrtle Beach area. I only have 5 trucks now.

 

[amscontr]

Like they say about dump trailers, "There are those that have and those that will". Flipped 2 of them myself both frame and frameless trailers.
Like everyone else said be careful where you dump especially in a landfill. Back in and pull forward a time or two the see how solid/stable the ground is. Some people use a "Plumbob" on their trailers to keep an eye on as they're raising their trailer.
Hauled many loads of Demo Debris, Scrap, Brush, etc. in frameless dumps. Sometimes I'd use the trailer brakes and sometimes set the tractor brakes. A lot will depend on the surface if your trailer pulls your tractor with the trailer brakes applied or if the tractor is in soft ground when raising you might try letting the trailer roll forward as it empties the load it will continue to empty. Sometimes you just have to do both so the materials empties out. A lot depends on your trailer if all 4 wheels stay on the ground or if it sits on the back axle and the strength or type of draft arms. Some trailers have flimsy lightweight arms and some more rigid.
It's like anything else once you get past that halfway point the law of physics will win. If it starts to lean you might get lucky and get it to drop without any issues. Keep in mind wind also plays a factor in dumping also.