WDH and airbag setup Question

Ron Gratz wrote:

RinconVTR wrote:
You wont find anything but opinions to air up before applying the WDH, and you asked the right questions challenging this. It is simply not logical to lift the rear prior to applying the WDH.

All formal instruction will tell you to air up (or turn on auto-level) after WDH is applied. Its just not easy to find online. The link to eTrailer previously posted is a good start.

Ford and GMC/Chevrolet seem to disagree with you.

GMC/Chevrolet typically specifies:

If a weight?distributing hitch is being used, it is recommended to allow the shocks to inflate, thereby leveling the vehicle prior to adjusting the hitch.

Ford typically specifies:

When connecting a trailer to a vehicle with automatic leveling suspension using a weight-distributing hitch, always use the following procedure:
1. Load the interior of the vehicle to a weight similar to that which you intend to carry when towing. This includes things such as passenger weight and cargo.
2. Drive the vehicle for approximately 2 miles (3 kilometers) to re-level the suspension.
3. Park your vehicle, without the trailer, on a level surface.
4. Measure the height to the top of your vehicle’s front wheel opening on the fender. This is H1.
5. Attach the trailer to your vehicle without the weight-distributing bars connected.
6. Make sure you securely attach and lock the trailer tongue to the hitch.
7. Install safety chains, lighting, and trailer brake controls as required by law or the trailer manufacturer.
8. Drive the vehicle and trailer at 20–25 mph (32–40 km/h) for approximately 2 miles (3 kilometers) to re-level the suspension.
9. Park your vehicle and trailer on a level surface.
10. Measure the height to the top of your vehicles front wheel opening on the fender a second time. This is H2.
11. Install and adjust the tension in the weight distributing bars so that the height of the front fender is approximately halfway between H1 and H2.
12. Check that the trailer is level or slightly nose down toward the vehicle. If it is not, remove the trailer, adjust the ball height accordingly, and repeat Steps 5 -11.

The main thing to know is:
1) IF YOU ADD AIR TO THE BAGS AFTER ADJUSTING THE WDH, YOU LIFT THE REAR OF THE TV, AND
2) IF YOU LIFT THE REAR, YOU DECREASE THE LOAD TRANSFER TO THE FRONT.

Therefore, if you add air AFTER the WDH is adjusted, you change the adjustment.

But, it doesn't matter whether you add air first and then adjust the WDH or whether you adjust the WDH first and then add air -- as long as you know how to use the WDH and bags in conjunction with each other.

You can add air first, and then adjust the WDH to return the front of the TV down to the desired height.
OR
You can over-adjust the WDH first (making the front end go below the desired height) and then add air to bring the front end back up to the desired height.

Whichever way you choose to go, you probably will need to do some "experimenting" to determine how much air to add initially OR how much to over-adjust the WDH initially so both the front and rear of the TV end up at the desired heights.

Ron

Good find, but lets be very clear. This instruction is for the OEM's auto-level system. Not aftermarket air bags which the OP has.

And what trucks or SUV's are these statements referring to?

Where are the links to the source, what is the source? Towing guide? Owners manual?