WD Question For Ron

[Bob_Landry]

If you have a conventional tow trailer with a tongue weight of 1000 and with a properly adjusted WD, 300lbs is transferred back to the steering axle and the remaining 700lbs is transferred back to the trailer axles, how much weight have you added to the payload of the truck besides the weight of the hitch?

[Ron_Gratz]

In theory, to achieve 100% restoration of the load removed from the front axle,
the amount of load transferred to the TT's axles is a function of:
1) the distance from the TV's rear axle to the ball (call this D1), and
2) the distance from the ball to the midpoint between the TV's axles (call this D2).

To achieve 100% restoration of the load removed from the front axle, the percentage of tongue weight transferred to the TT's axles is given by:

Percentage = 100 X D1 / (D1+D2)

For a typical value of D1 = 65", the percentages for various values of D2 are given in the following table:

D2 (inches) Percentage

-----160----------29%
-----180----------27%
-----200----------25%
-----220----------23%
-----240----------21%
-----260----------20%

I agree that percentages obtained from scales data tend to be closer to 20% than to 25%.
This suggests that, in many cases, front axle loads are not being returned to their unhitched values -- either intentionally or unintentionally.

Ron

[APT]

Find some examples of people that have done the 3-passes to help you understand how trailer tongue weight affects the TV axle weights and how the WDH works.

Link 1
Link 2

And look at the link within Link 2.

So 1000 pound TW might add 1500 pounds to rear axle without WD and remove 500 from front axle. To add that 500 back to front axle using a WDH would remove about 750 from rear axle and add 250 back to trailer. 25% seems a bit high compared to scaled examples I have seen. 20% seems more typical for pickups/TTs. And with Ford and now GM's recommendation of only restoring 50% of lost front axle weight, the rear axle weight stays higher as well as less weight transferred back to trailer.

[jerem0621]

I use to do a lot of guessing too.

The real answer for You and Your rig is to go to a scale, get an unhitched weight, then get a trailer weight (that way you have actual numbers) then weigh the entire rig all hitched up. That will tell you how your weight is distributed.

Hope this helps

[LarryJM]

One thing to remember is that while only 850 in Ron's example is added to the TV payload the full dead tongue wt. (1000lbs) and wt. of the WDH/drawbar (assume about 100lbs) go against the receiver ratings. Thus in this example the tongue wt. rating of the receiver should be around 1100lbs (1000lbs dead tongue wt. and approx. 100lbs for the WDH/drawbar combo).

Larry

[Ron_Gratz]

Bob Landry wrote:
If you have a conventional tow trailer with a tongue weight of 1000 and with a properly adjusted WD, 300lbs is transferred back to the steering axle and the remaining 700lbs is transferred back to the trailer axles, how much weight have you added to the payload of the truck besides the weight of the hitch?

In order to transfer 300# back onto the steer axle, the WDH would have to transferred about 150# to the TT axles and would have removed about 450# from the drive axle.

You would have added about 1000-150 = 850# to the TV, not including the weight of the hitch.

Ron

[SoCalDesertRid1]

K Charles wrote:
If yo have a trailer with a a tongue weight of 1000 lb and you put it on your hitch then you added 1000 lb to your payload.

Correct, before application of weight distributing spring bars. After spring bars are hooked up, some weight is transferred to trailer axles, as Barney stated.

[Bob_Landry]

Ron was the first guy who came to mind, but any good answer is appreciated. I'm not arguing, I'm asking. I'm trying to understand how weight that is transferred from the hitch to the trailer axles has to be subtracted from the trucks payload. It seems like it just goes back to the trailer.

[SoCalDesertRid1]

TomG2 wrote:
...What you asked is not reality. One would not want to transfer all thousand pounds off the rear axle, even if it were possible.

Agreed.

[SoCalDesertRid1]

BarneyS wrote:
I think I am right in the following. If not, I'm sure Ron or somebody else will be along to correct me. 🙂
Roughly speaking you have added around 700lbs to the payload.

That 300lbs that was transferred back to the truck front axle is weight that was leveraged off of it by placing the tongue on the ball, not weight added from the tongue. The weight on the axles before drawing up the WD bars would be around 1300lbs - 1000 from the tongue and 300 from the front axle of the truck.

Then about 300lbs of the 1000lbs is transferred back to the trailer axles leaving about 700lbs of the 1000lbs left on the truck to be subtracted from the trucks payload.
Barney

That is correct.

[TomG2]

You may want to PM Ron, if his is the only answer you are looking for. What you asked is not reality. One would not want to transfer all thousand pounds off the rear axle, even if it were possible.

[BarneyS]

I think I am right in the following. If not, I'm sure Ron or somebody else will be along to correct me. 🙂
Roughly speaking you have added around 700lbs to the payload.

That 300lbs that was transferred back to the truck front axle is weight that was leveraged off of it by placing the tongue on the ball, not weight added from the tongue. The weight on the axles before drawing up the WD bars would be around 1300lbs - 1000 from the tongue and 300 from the front axle of the truck.

Then about 300lbs of the 1000lbs is transferred back to the trailer axles leaving about 700lbs of the 1000lbs left on the truck to be subtracted from the trucks payload.
Barney

[Old-Biscuit]

Here is a link to Ron's post back in Aug of '04 explaining it all

Ron's POST

[K_Charles]

If yo have a trailer with a a tongue weight of 1000 lb and you put it on your hitch then you added 1000 lb to your payload.