Air bags

[Chomperoni]

I just installed firestone air bags on my f150.
I have a weight distribution hitch.
Do I hitch the trailer and put WD hitch first or pump air bags then hitch?

[mcfarmall]

Doesn't really matter. If you pump after hitching you won't have to crank the tongue of the trailer up as high.

I leave 10 psi in my air bags year round and pump them up to 25-30 before I hook up. My reason to pump before hitching is so that my tongue mounted spare tire doesn't drag the apron when I pull out of my shop building. I don't attach the spring bars until I'm ready to hit the road, for maneuvering around the house I leave them off.

[Camper_bob]

Just make sure that when you adjust your hitch, your bags are where they will be when traveling. I just installed RAS on mine and the hitch manufacturer recommended I start from scratch setting up my hitch after installation of ANY suspension component.

[mcfarmall]

I didn't change anything on my WDH setup after I installed the air bags....didn't need to as the truck/trailer still sat in a straight line. The only difference I noticed was the rig felt more solid going down the road. Perhaps some situations may be different than my experience.

[Chomperoni]

So I should pump the air bags to 30-40 pounds then set up the wdh?
I am guessing the main issue is that the truck is level. Is it?

[Camper_bob]

Originally Posted by Chomperoni

So I should pump the air bags to 30-40 pounds then set up the wdh?
I am guessing the main issue is that the truck is level. Is it?

This is what was recommended to me by my hitch manufacturer. And it makes sense. Before you install suspension parts, the sag of your rear end contributes to the dynamics of the tension in the hitch and how the bars distribute weight fore and aft. After you install suspension parts, those new parts are taking up some of the slack (or sag in this case) and thus the dynamics that contribute to the weight distribution have changed. The spring bars may not have as much tension in them (and thus are distributing less weight) because they're no longer the only link in the chain so to speak. Logically it follows that you'll have to re-tune your hitch setup after you install any suspension parts (helper springs, RAS, air bags...) that change the characteristics of the rear-end of your truck.

All that being said, the only way to tell for sure if you're WDH is properly setup is on a scale. I have not weighed mine since I added the hardware and re-configured my hitch, so I don't know where I am. But based on fender measurements I should be fine. Fender measurements got me just about perfect the first time I set the hitch up, and it feels fine towing so far, so I'm not in any real hurry to weigh it... I'll do it later this spring on one of our first trips of the season to find out for sure.

Also note, level after setup does not necessarily indicate proper weight distribution. You need to weigh the TV, and then weigh the rig with spring bars engaged to determine if the WDH is returning the proper amount of weight to the steer axle of the TV.

[RedHorse1]

I think Camper has the key here. We did not use air bags on our TV when we owned the TT but it seems to the that "level" should be a combination of lift provided by the bags and the WDH. If all the lift is provided by the bags then the WDH is not transferring any weight from the rear axle to the front. So even tho everything is level the rear axle could be overloaded. If the WDH provides all the leveling force then the bags would have minimal pressure in them and providing little suspension assist.
Back to Camper's point, hitting the scale is the only way to know for sure how it's dialed in.

[mjlaupp]

My WDH mfg. instructions for a TV with air bags was:

1) Load the TV with cargo.
2) Level the TV with the air bags.
3) Hook up to the trailer.
4) Level the TV & TT with the WDH bars.

Thus the air bags support the TV cargo and the WDH supports only the TT tongue weight and the WDH weight.
The WDH capacity should equal the TT tongue weight.

If there are no air bags, then the WDH capacity should equal the TT tongue weight plus the weight of cargo placed behind the rear axle of the TV.

[Chomperoni]

Thanks Guys

[Bob Landry]

There is a misconception that gets repeatedly posted because someone read it on the Internet, and that is the WD bars are used to level the TV. If anyone has read that, please scan it and post if for all of us to see because I have never read that in any WDH setup instructions nor have I heard it in any setup video. The purpose of the WDH is to transfer weight back to the front axel that was removed by the weight of the trailer, nothing else. If you have to have your TV level, do it with bags and then adjust the WDH. The reason the bags affect the hitch adjustment is because changing the height of the truck's rear changes the amount of tilt on the hitch head and that's how the hitch is adjusted, not until it looks right, or drives better, or is level.

[Jmooney]

. You are right. I would also add, that you can also put too much weight forward. , or too much weight on the back of the TT as well if your WDH is over sized and over hung. ( under full position of chain links )

Level from TV front bumper to TT rear bumper is the goal.

[Rustic Eagle]

Originally Posted by Bob Landry

There is a misconception that gets repeatedly posted because someone read it on the Internet, and that is the WD bars are used to level the TV. If anyone has read that, please scan it and post if for all of us to see because I have never read that in any WDH setup instructions .....snip

Unfortunately I have run cross it from time to time in WDH instructions, and it can be misleading and/or confusing depending on how the level vehicle inference is used in concert with adjusting chain links (via WD bars).

Some examples:

Blue Ox states: "Determine if the towing vehicle is level. If necessary, adjust the chains links."..... "Repeat the above steps until the towing vehicle is level." (referring to chain adjustment).
Reference: Page 5: http://blueox.com/Uploads/Docs/BXW03...,1504,2004.pdf

Curt states: "Vehicle should settle evenly, within 1/2". Re-measure the front and rear bumper reference points. If the front has settled much more than the rear, increase the number of chain links between the lift bracket and the spring bar." Although it doesn't use the exact term "level vehicle", one could walk away with the implication.
Reference: Page 4; https://www.curtmfg.com/masterlibrar..._17330_INS.PDF

EAZ-Lift states: "By adjusting the chain links up or down, the desired levelness of the car and trailer will be gained. Remeasure front and back of towing vehicle and have both settle the same amount or up to an inch lower in back by adjusting chain on Spring Bars." Implying that chain adjustment be used to level the trailer was interesting here as well.
Reference: Page 4: http://manuals.adventurerv.net/Eaz-L...structions.pdf

As we all know the objective of the WDH is to return the integrity of the TV's front suspension to it's unhitched condition, and/or per Vehicle Owners Manual specifications when using a WDH.

Bob

[TCNashville]

I had to do a hitch re-adjustment after installing the Timbren SES on my F-250, and I must say that it's a lot easier to hook up with the Timbren application.