Using Air Bags with a WDH

bpetroni · 07-31-2013, 04:26 AM

I installed a set of Air Lift bags on my 2012 Ram and would like some set up tips. I use a WDH when towing my trailer which weighs about 5K dry. I was wondering if a should load my bed and pump up the air bags to remove the sag and then use the WDH to level the trailer & truck or? Also I was wondering what pressure you guys who have use the Air Bags run them at with a heavy load?

Thank You

Essness · 07-31-2013, 04:46 AM

Bp, I have the same truck as you with the same bags. I'm afraid there is no easy answer to your question. If I load a cart in my trailer (I have a toy hauler) it makes my tounge lighter by about 70 to 100 lbs. I only run about 12 to 15 lbs of pressure in the bags just to stiffen the ride a little. With no cart in the back of the trailer I run the bags at about 30 to 35 lbs for the same reason.
The WD settings remain the same with or without the bags. At least for me...........

bpetroni · 07-31-2013, 04:51 AM

The cart actually makes the togue weight lighter? Is that becuase it is behind your rear axle?

Essness · 07-31-2013, 04:52 AM

Quote:

Originally Posted by bpetroni

The cart actually makes the togue weight lighter? Is that becuase it is behind your rear axle?

That's correct.

My wheels are in front of the back steps......

bpetroni · 07-31-2013, 05:39 AM

Quote:

Originally Posted by Essness

That's correct.

My wheels are in front of the back steps......

I did not know that, I'm trying to learn all I can about making my rig as safe as possible for towing.

dankent · 07-31-2013, 05:43 AM

When i had the 1500, I also would load up the air (TLC system same idea) when everything was loaded and WDH was allready set up .. only to stiffen the ride up. I allways took a measurement before and after and as long as i was not over my first measurement.

Essness · 07-31-2013, 05:52 AM

Quote:

Originally Posted by bpetroni

I did not know that, I'm trying to learn all I can about making my rig as safe as possible for towing.

Understood. I still spend a lot of time reading about towing, weight dist., and sway control. I figure the more I know the better I'll be!

Bob Landry · 07-31-2013, 06:06 AM

There is a simple answer to this, but first some misconceptions have to go away.

One is that WD is used to level the truck and trailer. It's not. The ONLY purpose of WD is to return the correct amount of weight to the steering axle after hitching the trailer to the TV. NOTHING ELSE! You can determine that weight by going to the scales, or by fender measurements, but that's where you need to be. If you are going by measurements, you can get that from the truck's manual. If you start tweaking it to get the truck level, you might as well not have it because it's not doing any good.

Secondly, air bags do not affect any of the capacities of the truck. You still have the same amount of weight on the rear axle. You still shouldn't exceed the payload of the truck and you can't pull a heavier trailer just because you have air bags.

The WD has to be adjusted with the bags already inflated to the pressure you are going to use towing. If you change the air pressure, you change the height of the rear of the truck which changes the angle of force on the bars which changes the amount of weight being returned to the front axle. Then you have to readjust the WD. It's not rocket science, but it does have to be done by the book.

Essness · 07-31-2013, 06:13 AM

Quote:

Originally Posted by Bob Landry

There is a simple answer to this, but first some misconceptions have to go away.

One is that WD is used to level the truck and trailer. It's not. The ONLY purpose of WD is to return the correct amount of weight to the steering axle after hitching the trailer to the TV. NOTHING ELSE! You can determine that weight by going to the scales, or by fender measurements, but that's where you need to be. If you are going by measurements, you can get that from the truck's manual. If you start tweaking it to get the truck level, you might as well not have it because it's not doing any good.

Secondly, air bags do not affect any of the capacities of the truck. You still have the same amount of weight on the rear axle. You still shouldn't exceed the payload of the truck and you can't pull a heavier trailer just because you have air bags.

The WD has to be adjusted with the bags already inflated to the pressure you are going to use towing. If you change the air pressure, you change the height of the rear of the truck which changes the angle of force on the bars which changes the amount of weight being returned to the front axle. Then you have to readjust the WD. It's not rocket science, but it does have to be done by the book.

Agreed. Just to be clear, my previous post says that the wd settings dont change. What I mean by this is that you set up your wd the same way with or without air bags.

Bob Landry · 07-31-2013, 06:24 AM

Quote:

Originally Posted by Essness

Agreed. Just to be clear, my previous post says that the wd settings dont change. What I mean by this is that you set up your wd the same way with or without air bags.

But that's not true. If you change the inflation of the bags after the WD has been adjusted, the change in the height of the rear end changes the angle of hitch ball tilt and that is what's going to change the amount of weight that is shifted.

Essness · 07-31-2013, 06:31 AM

Quote:

Originally Posted by Bob Landry

But that's not true. If you change the inflation of the bags after the WD has been adjusted, the change in the height of the rear end changes the angle of hitch ball tilt and that is what's going to change the amount of weight that is shifted.

Correct, then you would have to reset your wd to accomodate the change in height. But the way you set up the wd remains the same based on settled height determined by bag pressure. You should never change inflation without re-setting the wd to accomodate.

We are saying the same thing, I'm just struggling to say it.

Randy_K · 07-31-2013, 09:00 AM

I often change my payload in my truck but have not changed the WD set up. They were set up at the dealer with the bikes in the truck. When I have my motorcycles in the truck < 700 lb> I run 25 psi in the air bags. When I do not have the motorcycles I run 10 PSI. I do find that the truck handles slightly better with the Motorcycles in the back of the truck.

I think it would be hard to change things all the time. In one week I can go from one bike , two bikes or no bikes.

Randy

Essness · 07-31-2013, 09:08 AM

For me, it's just a matter of how many links on the chains. Once I get it set up the first time with varied pressures and loads, I just need to remember what worked and be open to the idea that I may not have remembered correctly

audio1der · 07-31-2013, 09:14 AM

I always air mine up to 30lbs before hitching, and used that setup when playing with my hitch head angle and height. Now it's very consistent, and absolutely night & Day different than how the dealer had it set up for us the day we bought it.
The bags will absolutely have an effect on rear end ride height which equates to hitch head angle, so its important to know your setup. With the minimum 5psi in the bags we ride on the bumpstops (truck is lowered). At 30psi we maintain 2.5" of clearance to the bumpstops.
I think towing with a fourth gen RAM 1/2 ton should be mandatory to have airbags of some kind.

Bob Landry · 07-31-2013, 02:31 PM

Quote:

Originally Posted by Essness

For me, it's just a matter of how many links on the chains. Once I get it set up the first time with varied pressures and loads, I just need to remember what worked and be open to the idea that I may not have remembered correctly

Most , if not all, of the hitch manufacturers will specify a recommended number of links under tension. With Reese, it's five and for most applications, they think that will eliminate interference between the bars and the tongue. Unless you are at either end of the tilt adjustment, you should be able to adjust for different loads without having to change the number of links.
The main thing is that you know how to adjust it properly and know when to leave it alone. It's tempting to tweak to see what happens, that is, the truck drives better(usually perception), making the truck level, etc, and as soon as you do that, your measurements go out the window and you may as well not have bothered with it. By adhering to the specs for truck and the instructions for the hitch, you always get the right amount of transfer, even though it may not "feel right". Too little transfer and the front end is light and can get squirelly in bad conditions, too much and you accelerate wear on the tires and suspension components.
Changing the level of the trailer is going to have some effect, but it's going to be negligible. If you followed the hitch instructions, you are going to start off with the trailer pretty close to level from the start.

bpetroni · 07-31-2013, 08:53 PM

I did not notice it before but my WDH (EAZ Lift Elite) has a instruction section just for using the WDH with Air Bags, duh...thanks for the advice!

PROPER METHOD OF HOOKING UP WEIGHT DISTRIBUTING
HITCH WITH AIR SHOCKS OR AIR BAGS
A. Air shocks or air bags should only be used to support the
added weight you load in the back end of tow vehicle.
B. After you have adjusted the shocks, measure distance
between rear bumper and ground, write it down.
C. Measure distance between front bumper and ground,
write it down.
D. Hook up trailer to towing vehicle.
E. Raise front of trailer and back of towing vehicle above level
with trailer tongue jack (approx. 3").
F. Secure spring bars to Hook-Up Bracket.
G. Release trailer tongue jack.
H. Remeasure front and back of towing vehicle and have both
settle the same amount or up to 1/2" lower in back by
adjusting chain on spring bars.
I. CAUTION: Do not adjust air shocks or air bags to support any
of the tongue weight of trailer.
J. You have now distributed the trailer tongue weight on both
axles of the towing vehicle.
K. See step 7 on page 4.
1

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