OP, set your phone with the CAT Scale app. To test, is the thing. For that a numerical baseline is needed.
A WDH is only partly about being a hitch. It’s an aid to steering control. It also improves braking.
1). TARE Weight. Take a cold tire pressure reading first. Max the fuel once at the truckstop. With driver alone and nothing in the truck EXCEPT what remains there to the day you sell it, get a scale reading. (The paper copy is at the fuel desk inside).
- The published shipping weight means little. The TARE weight is the lightest it will ever be. Take a pic of the door sticker showing axle/tire/wheel ratings.
- With the tire Load & Pressure table (and inside truck limits) pressurize the tires to reflect the values acquired.
2). Another day, but again with a cold tire reading, trailer in tow, both vehicles loaded for camping (plus fully topped propane & fresh water) max the fuel tank and cross the scale. All passengers aboard. Again, acquire the ticket.
3). With no changes except to have dropped the trailer, cross the scale again. Everyone still aboard. Acquire ticket.
4). Adjust truck tires to book value. Trailer tires to sidewall max.
Generally speaking, the benefits of a WDH start with a 350-lb TW (my Cummins diesel operator manual requires it at that point). Understand that pulling weight down the highway is nothing. The hitch rigging (as it were) IS A STEERING COMPONENT.
Where the trailer in question is low to the ground and presents little surface area to crosswinds, it’s not the weight of a trailer that gets operators into trouble, it’s the wind load of a high-riding box.
That typical box riding on leaf springs has little to no wheel travel, and the design TRAPS winds (versus a radiused Airstream) such that with slide outs (imbalance) and a very tall floor height, it’s the least stable vehicle on the road. Bad design & **** suspension make it terrible.
To tow without WDH is done everyday. But, why? Braking distances are increased, not decreased, ride motions are exaggerated, and steering is wonky.
The leading cause of loss-of-control accidents with towed RVs is adverse winds. Natural, or man-made. The rear of a box TT will come off the ground in a sway event (which is better pictured as oscillation where a widening cone starts at the hitch ball and extends back) and in only a moment, the TV rear tires lose contact. That’s the end.
The operator tried to stay upright. Overcorrects. Wrecks.
It wouldn’t occur to me to tow a billboard thru the wind without a WDH (integrated away control). As it stands, I can take my 63’ long, 17k combined rig and do maneuvers all day at 55-mph that following me would cause you to have that wreck before completing the first one.
That my rig stops sooner Towing than the loaded truck does Solo, is enough.
As a truck driver running in excess of 10,000 miles/month I see the rigs that struggle with crosswinds. Or, in coming up over a major river crossing with a wicked wind coming downstream. And we are WAAAY up in it above ground level. It’s a problem for me even with 46,000-lbs in the box.
The original WDH is the Reese. Still the best of the type. But made obsolete by the design patented by Jim Hensley a quarter—century ago. No sway. Ever. Cheap at twice the price.
So, the above work outlines the basics of static measurement. What happens on the road is dynamic. That trailer tongue effectively starts back between the tandem axles. A very long lever. Wrong conditions and it’s exerting several thousand pounds of force. Thousands, not a few hundred. All of it onto the hitch ball.
A WDH spreads the force. Over three points, not one. Down on the hitch ball — OR UP —the force is mitigated so far as Steering feel is affected.
My truck, solo, ready to hitch, is at a 50/50 weight balance. After tension applied, the Steer Axle is close to the solo value. The Drive Axle still outweighs it (important) by 10% or a little more. Weight has been shifted to the TT tires which increases their grip resisting side-sway, and improving braking.
My TT TW does NOT exceed the receiver rating (been upgraded). So what?
What matters is Steering, Handling, and Braking. That which improves those reduces risk of accident & injury. It makes my day at the wheel far easier. Uneventful.
So, start as above with the scale tickets from two different days. Do it correctly. Don’t adjust truck tire pressure past Table values (as that reduces tire grip; it’s what the dummies do to try and modify handling), and take it out for a trip.
WDH by itself gives a tiny bit of anti-sway. The hitches with integrated antisway exert about 150-lbs of resistance. A Hensley or Pro-Pride simply eliminates the problem altogether.
A tow rig is composed of three EQUALLY WEIGHTED items: TV, TT and the hitch rigging. That last is as important as the other two.
The new guys with twenty years haven’t towed with a well-designed rig and don’t know what’s possible. No reference. A new 1974 Holiday Rambler with lower clearance height than today’s pulled behind a Dodge Monaco was a tow rig better than what they’ve ever experienced. (Can’t get the WD adjusted properly either, so not much help despite good intentions ). Do your own investigation getting the correct numbers and doing the tests.
1). How fast can you do an emergency double lane -change? 35-mph? I can do them unceasingly at 55-mph. Start with starboard tires on Interstate shoulder and violently cut over to opposite outside edge of passing lane. And back. Throttle-on the whole way.
2). Whats the difference in braking distance from 60-mph in an emergency stop from the solo, loaded for camping condition, to that with the trailer also loaded?
3). What conditions experienced underway are those where you are forced to stop. Be specific. Know them ahead of time. Have alternates planned.
I have towed my 35 TT in 45-mph crosswinds with higher gusts where the big trucks are all leaving the road. This is after the RVs disappeared. The point here is that my hitch rigging was as important as both the TV & TT. The limits have to be found, and known. (Once the big trucks left, so did I. But at an exit of my choosing).
Here’s a further clue in advance: Ideally, the Drive Axle will weigh more than the Steer once hitched. Traction. Without WDH this means the solo TV will be light on the Drive. . . . what happens to Drive traction when the TT is pitching and the tongue is on the upward swing?
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