Rear air bags and WDH setup

[Glenn141]

Are there any setup tips for towing with air bags on the rear plus a WDH? Want to install timber grove AB's on the Ram with a 2" level kit up front and some 10 ply tires in preparation for towing my TH.

[SeaDog]

there is no special setup that I know of when using air bag.
with the trailer level on level ground measure the height from ground to top of coupler
With the truck loaded for camping measure the front fender well height
adjust the ball on the WDH to be aprox 2" above the coupler height and hookup
measure the fender well and adjust the bars to bring the fender well to within 1/4 of first measurement.
this is the basic procedure finer adjustments can be made by tilting the ball
not sure if this is what you were looking for its the basic procedure I use.

[Glenn141]

Originally Posted by SeaDog

there is no special setup that I know of when using air bag.
with the trailer level on level ground measure the height from ground to top of coupler
With the truck loaded for camping measure the front fender well height
adjust the ball on the WDH to be aprox 2" above the coupler height and hookup
measure the fender well and adjust the bars to bring the fender well to within 1/4 of first measurement.
this is the basic procedure finer adjustments can be made by tilting the ball
not sure if this is what you were looking for its the basic procedure I use.

I guess what I'm wondering is how to determine how much pressure to run in the bags and its affect on setting up the WD hitch? Would the WDH setup not be different on a bagged TV vs a non baggedTV?

[Jim34RL]

I am not familiar with the set-up for air bags and a travel trailer with a WDH. But this is my way of determining the correct air pressure for my needs when towing a 5th wheel.

My set up is as follows when towing. My truck is a HD 2500 with the Cummins 6.7L diesel. My towing tires are LT285/70R/17 126R Nitto Dura Grapplers which are a 10-ply tire. My air pressure in the rear tires is set at 70 PSI which will support a load of 3415 LBS each, the front tires are set to 55PSI which will support a load of 2890 LBS each.

You will need to weigh your truck and trailer to know what air pressure you will need in your tires. Using a tire inflation tire chart for your tires to achieve the proper air pressure to carry the load that the trailer will add.

When I hooked-up my 5th wheel for the first time. I measured the rear bumper height before the trailer was attached. I recorded this measurement, I than attached the 5er to the truck. I inflated my air bags to achieve the same measurement that I had at the rear bumper, noting the air pressure to achieve this ride height, for futire use.

I then towed the trailer and noted the ride quality of the truck at this air pressure. I lower the air pressure by 5LBS and achieved a much more improved ride in my opinion.

My suggestion would be to play with the trailer and air bags with the WDH adjusted to achieve the correct bumper height. As measured before hooking up the trailer. Then adjusting the air bag pressure to improve the ride You may need to readjust your WDH a little to keep the truck level if required.

Good luck.

[007matman]

The general consensus among manufacturers that I've seen is that the bags should be either deflated or at standard pressure prior to setting up the WDH. You'll take measurements as part of the proper setup and the goal is to settle the truck as much as possible both front and rear without the need to put more air in the rear.

After it's adjusted, you can add a little to bring the rear back up to level out the vehicle.

[mikeyk101]

I have a Chevy Silverado with 2" level kit on front and didn't do anything to rear suspension at first. I had my WDH dialed on perfectly on front but with the sag in rear, it caused headlights to point skyward. I was getting about a 2" drop in rear which would normally be perfectly acceptable if I had the stock rake. But because the front is now 2" higher, the rear sag of 2" was not good. So like you are contemplating, I added the Airlift airbags on the rear. I added air to raise the rear about 1-1/2 to get the rake back unhitched. I think it was around 20lbs psi. I then hitched up the camper using the WDH. The front was at slightly lower than 1/4" of unhitched height but the rear was now only about a 1/2" lower than pre air bag height. This took care of the headlights and now they project down the road as they are supposed to.

So the key is to figure out the height of rear before hitching and then see how much sag you get after hitching up. Either way with or without air bags you will probably be about a 2 inch sag. You should then while unhitched, add air to get the rear end up about 1-1/2". Then after hitching up make sure that the front is where it needs to be and you should find that the rear will probably only have dropped about 1/2". This is what works for me.

[awellis3]

Originally Posted by Glenn141

Are there any setup tips for towing with air bags on the rear plus a WDH?

Yes. Set the air bags' pressure to the manufacturer's minimum pressure requirement. (On my Firestone bags that's 6 psi) Set up the WDH following the manufacturer's instructions.

[boogiejack75]

If it were me, I would skip the leveling kit and the air bags. You shouldn't need air bags with a properly adjusted WDH. In fact, most WDH manufacturers recommend not using air bags. As for the leveling kit, it just works against the WDH, as described in a post above.

[mikeyk101]

Originally Posted by boogiejack75

If it were me, I would skip the leveling kit and the air bags. You shouldn't need air bags with a properly adjusted WDH. In fact, most WDH manufacturers recommend not using air bags. As for the leveling kit, it just works against the WDH, as described in a post above.

Once the leveling kit is put on, it's a bit of a chore to go back. As far as why I did it on mine, it was so I could get larger tires on mine. I have 20' rims and a little more rubber between the rim and road helps with the ride. I went from 31.9" tires to 33" tires. Without the leveling kit, the 33" would most likely be rubbing.

[ARhappycamper]

Originally Posted by SeaDog

there is no special setup that I know of when using air bag.
with the trailer level on level ground measure the height from ground to top of coupler
With the truck loaded for camping measure the front fender well height
adjust the ball on the WDH to be aprox 2" above the coupler height and hookup
measure the fender well and adjust the bars to bring the fender well to within 1/4 of first measurement.
this is the basic procedure finer adjustments can be made by tilting the ball
not sure if this is what you were looking for its the basic procedure I use.

Do this set up with the airbags empty and then when all hitched up you add air to the bags for stability.

[reeston]

I followed this guys setup to a “T” and it was as close to perfect as I could get.
https://youtu.be/O3CAKb18ZXs

[NJBreeze]

I think you should know that the levelling kit is fighting the WDH. The airbags would screw things up even more. I'll assume you at least want to keep the levelling kit so--

You need to go to a scale. With trailer on truck and W/o the WDH engaged measure your rear drop and take note of the front and rear axle weight on the truck. Now get off the scale, engage the WDH , then back on the scale and see if you have reduced the drop on the rear and have added weight to the front axle while removing it from the rear. The WDH should move say 10% to 15% of the weight from the rear and put it on the front. You should also maintain a drop of less than 2" and closer to 1" is probably best. This is how you correctly setup any WD hitch , e.g see how much weight it is actually distributing!!!

The WDH is moving weight like a seesaw from the rear axle to the front axle with the fulcrum being the rear axle. So in effect with the levelling kit your telling the WDH not to move that weight. With the air bags your telling the WDH not to move that weight. So long story short for each $$ you spend on levelling and airbags you getting less and less value out of them if any at all. Sorry but it is simple physics and geometry. I guess I can understand the levelling kit but the airbags are a complete waste of money. Go and get a great pair of Bilstein shocks and that will be so much better than airbags. Best of luck!!