8100hd

kehyler

Ok. Another thing I don't understand, is the percent tongue weight before or after the weight distribution has occurred?

8100hd

kehyler

I thought WDH worked by distribution some weight off the rear axle of the truck, and onto the trailer's axles and the truck's front axle? If that is true, then doesn't tongue weight change?

8100hd

kehyler

I still don't understand what you are trying to tell me, sorry! The rear of the truck squats less with a WDH, so how can it be that the weight that the trailer tongue is exerting on the hitch has not been reduced?

smokeywren

Because the weight of the WD hitch is not included in the specs of either the truck or the trailer. Remember that the goal of all this number crunching is to determine the maximum weight of a trailer you can tow with a specific tow vehicle without exceeding any of the weight ratings of the tow vehicle. So when computing anything about towing with a truck and trailer, you must add the weight of the WD hitch somewhere. Trailer specs include dry weight and cargo carrying capacity (CCC), but ignores the weight of the WD hitch. Receiver hitch specs note whether a WD hitch is required, but ignores the weight of the WD hitch.

When you weigh the wet and loaded rig on a CAT scale, the weight of the WD hitch is going to show up mostly as an increase in the weight on the rear axle - not the trailer axle(s). You cannot ignore that extra weight because it's looking you right in the face on the CAT sale ticket.

But also because most of the gross trailer weight does not effect payload capacity of the tow vehicle. Only around 13% of gross trailer weight affects payload capacity (i.e., increases weigh on the axles of the tow vehicle). But all of the weight of the WD hitch affects payload capacity. If you add the 100 pounds weight of a quality WD hitch to trailer weight, then only 13 pounds of payload capacity would be computed. But the actual payload capacity would be affected by all 100 pounds weight of the WD hitch.

8100hd

kehyler

Yeah, sorry, Im not finding this convincing enough to buy yet. The rear of the truck has to squat in proportion to the weight on the hitch. If the rear springs compress less, how can it be that there is the same weight on them?

smokeywren

Leverage.

The weight on the ball does not change, but the WD hitch distributes that weight to the front, rear, and trailer axles.

With a properly adjusted quality WD hitch, only about 50% to 60% of gross tongue weight remains on the rear axle. 20 to 25% is distributed to the front axle an another 20 to 25% is distributed to the trailer axles.

Study CAT scale tickets for a rig that has 1000 pounds tongue weight. One weighing without the spring bars installed, and another with the spring bars tightened per the instructions. You'll see that more than 1,000 pounds of tongue weight was on the rear axle without the spring bars installed, but only 500 to 600 pounds of tongue weight remained on the rear axle with the spring bars properly tightened. There will be more than actual tongue weight on the rear axle because without a WD hitch the front end will rise and distribute some weight off the front axle and back to the rear axle.