Weight Distribution Hitches

[Bird]

Corm, I'm sure you know that with any trailer, it is possible to have the towing vehicle hit the towed vehicle. So I guess the answer to your question is, "Yes, they can get in a bind", but it's usually not a concern because you usually will not cut that short anyway. Personally, I always used a separate friction type sway control. The old Reese lift bars with the cam type friction I guess worked OK but they were terribly noisy with the popping, squeaking, and creaking when maneuvering slowly. And of course if you greased them to stop the noise, you would also be reducing the friction and defeating their purpose. We had some friends who had that type of system, but I never wanted it, even though I know it works as intended.

 

[Redbug]

Corm...Bird is right, they do make some noises at times when making a real sharp turn, even though greased. But, I think the purpose of the chain is also to be movable with a load on them. You also want to position the arms, (by adjusting the chain length), so they are below the trailer "A" frame...when turning sharp, they swing under the frame...thus not hitting it.

 

[Corm]

Bird and Redbug, thanks for your responses. I've never used any kind of a W/D hitch before on either of my trailers, but I've been given one. I think I may start using it.

Corm

 

[Highbeam]

The system doesn't transfer significant tongue weight back onto the trailer. The purpose of the WDH is to create a moment or twist on the truck's hitch that will push its front axle down while lightening the rear axle. So you can add, say, 300 lbs on the front axle and lighten the rear axle by 250. The extra 50 lbs is a moment at say 20 feet forward of the hitch. The rear axles of the trailer will have to counter this moment but it's only 50 lbs at the same 20 feet aft of the hitch. You can efficiently move weight around on the truck axles with very little effect on the trailer axles.

Lots of people don't understand how these hitches work. They are very complicated and it hurts my head to try.

Most important thing is that the tongue weight doesn't significantly go away from the truck. You just move it around on the truck.

 

[FlaDon]

It's no so much that it's moving it from one trailer axle to the other, but it's moving some of the hitch weight back onto both trailer axles.

Many tandem trailer specs today have a gvw rating that is greater than the sum of the axle ratings. In that case part of the maximum load would have to be on the hitch. If that weight is too much for the truck and you used a WD hitch to make the truck ride better, then the trailer axles could become overloaded if the trailer were loaded to maximum gvw.

That's because some companies are fudging their weight ratings. A 7K rated trailer with tandem 3.5K axles should never weigh more tha 7K including the weight on the tongue.

Angle of the trailer in relation to the truck could put axles in an overloaded condition at times.

 

[downslope]

That's because some companies are fudging their weight ratings. A 7K rated trailer with tandem 3.5K axles should never weigh more tha 7K including the weight on the tongue.

Angle of the trailer in relation to the truck could put axles in an overloaded condition at times.

I agree with what you say about the weight ratings, but this "fudging" seems to be becoming more prevalent. It started with goosenecks and now I see some companies are using it on straight trailers as well. Except for a few manufacturers the majority of goosenecks being advertised today seem to have GVW's greater than the total of the axle ratings.

In some ways I have more confidence in a company that still does it the old way, but I guess others feel they have to do it to keep up with the competition and appeal to prospective customers who only look at the numbers.

The higher ratings could save you from a summons in the occasional overloaded situation, but on the other hand if I buy a trailer with 8K axles I might not want a rating over 16K if it pushes me into a more costly registration or CDL territory.

 

[Bird]

A 7K rated trailer with tandem 3.5K axles should never weigh more tha 7K including the weight on the tongue.

I don't know whether I'd agree or disagree with that. Supposedly two 3.5k axles should handle that much weight; i.e., 7k pounds, regardless of tongue weight. So I guess you could say I disagree. However, as a practical matter, I think your should allow yourself a little leeway, so I'd agree.

We lived for awhile, full time, in a 32' fifth-wheel travel trailer. It had two 3.5k axles. I didn't actually weigh it, and I had no problems, until I pulled it to Alaska in 1990. I broke one shock mount and ruined two tires on that trip. So I weighed it (yeah, I know, I should have weighed it a lot sooner and I learned) and found I had 7,300 pounds on the axles and 2,500 pounds on the fifth-wheel. I replaced everything from the frame down; 5,200 pound axles with 7k pound axle tubes on each, heavier springs, bigger brakes, stronger wheels and D rated radial tires instead of C rated bias ply.

 

[Duffster]

That's because some companies are fudging their weight ratings. A 7K rated trailer with tandem 3.5K axles should never weigh more tha 7K including the weight on the tongue.

Angle of the trailer in relation to the truck could put axles in an overloaded condition at times.

Fudging? Is there a written, or unwritten, law saying that a trailer has to be rated by the sum of its axle ratings?

I still say that a proper GVWR for a trailer is Axle ratings + Tongue load.:thumbsup:

 

[Diamondpilot]

Fudging? Is there a written, or unwritten, law saying that a trailer has to be rated by the sum of its axle ratings?

I still say that a proper GVWR for a trailer is Axle ratings + Tongue load.:thumbsup:

While I agree with you that its acceptable in most states I do not think that is the case in Indiana. I have never sold a trailer or seen a trailer that was originally titled in Indiana that allows more than the sum of the axles capacity on a BP trailer. 5Th wheel and GN yes, just not BP. Again I said originally titled in Indiana.

I know I have read it in a Indiana towing law book but can not find it but it stated something to the affect that 20% of the total load could be carried on the pin of a 5th wheel or GN but states nothing about BP. This in effect allows a 5th wheel or GN to have a GVWR 120% of sum of the axles.

Chris