Truck Sagging When Towing

tjcin wrote:
---I just watched the video and it's much more informative than the installation instructions.---

Which installation video did you view?

Ron

Terryallan wrote:
IF you use the bags to level the Truck, while hooked up. How will you know IF the WDH is doing any thing?????.---

When the front end is returned to the correct load or height, you know the WDH is properly adjusted.

If you want to adjust the WDH before adding air, you need to over-adjust" the WDH so both the front and rear ends are slightly below their unhitched heights. Then, adding air to the bags will cause both the front and rear to rise. The right combination of "over-loading" the WDH and added air can give a "level" TV.

If you want to adjust the WDH after adding air, you need to add air to the air bags so the rear end is slightly below its unhitched height. Then adjust the WDH to return the front to its unhitched height -- which will cause the rear to lift more. The right combination of air pressure and load transfer can give a "level" TV.

The instructions for adjusting the hitch on a vehicle with air ride, which is pretty much the same as bags, Goes like this. Go to a level spot. Unhook. Let the TV level itself. Turn the air ride / bags off. Adjust the hitch. Once it is done. Turn the air ride / bags back on.

I don't know what Ram specifies.

This is what Ford specifies for the 2013 Expedition:

Weight-distributing Hitch – Vehicles with Air Suspension

When hooking-up a trailer using a weight-distributing hitch, always use the following procedure:
1. If your vehicle is equipped with the Easy Entry/Kneel feature, turn it off using the information display.
2. Park your vehicle, without trailer and with the ignition on, on a level surface with all doors closed for a few minutes to make sure that the air suspension has settled.
3. Measure the height of the top of your vehicle’s front wheel opening on the fender. This is H1.
4. Attach the trailer to your vehicle. Do not install the weight-distributing bars at this time.
5. With the ignition on and all doors closed, let your vehicle (with trailer) sit for a few minutes to let the air suspension re-settle.
6. With the trailer connected, but without weight-distributing bars connected, measure the height of the top of your vehicle’s front wheel opening on the fender a second time. This is H2.
7. 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.
8. With the ignition on and all doors closed, let your vehicle (now with trailer and weight distributing bars connected) sit for a few minutes to let the air suspension re-settle.
9. Re-measure the height of the top of the front wheel opening, repeating Steps 7-9 as necessary to obtain a fender height approximately halfway between H1 and H2 after the air suspension has settled.
10. Check that the trailer is level. If it is not level, remove the trailer, adjust the ball height accordingly, and repeat Steps 4–10.

The Expedition manual also says:

If the system is off, the rear air suspension will not operate and will not raise (pump) or lower (vent) while the vehicle is not moving. However, if the system determines that the vehicle is low or high and needs to make a height adjustment while driving at speeds above 15 mph (24 km/h), the system will pump or vent as required. Normal vehicle operation does not require any action by the driver.

I interpret that to mean it will do no good to "turn off" the Expedition's rear ride height control, as it will continue to operate (above 15 mph) even if turned off.

The instructions for the 2013 Suburban/Tahoe state:

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.

As you can see -- neither Ford nor GM/Chevrolet specify that the ride height control should be turned off before adjusting and turned on after.
To do so would cause the rear of the TV to rise after the WDH is adjusted.
This would cause the amount of WDH load transfer to be decreased.

Ron

tjcin wrote:
Thanks for all the help. I just watched the video and it's much more informative than the installation instructions. I am not taking the TT anywhere until Labor Day weekend. Between then and now I am going to load the truck up and set it all up according to the video. I'll let you know how I make out. Tim C

tjcin,

I have a 2012 ram 1500 QC 4x4. I pull a 2012 Keystone Sprinter 266rbs. I also have airbags and an equalizer brand hitch with 1200lbs bars. My tongue weight is 900lbs per scale. I also have airlift 1000 airbags which fit inside the coils and were an easy install.

Since I have the equalizer hitch I rely on friction of the bars to eliminate sway so using airbags would cause more sway as less weight is on the hitch. I drop about 1.5" when all hooked up which brings back 400 of the 460lbs lost from the front end when wdh is hooked up. I still have approx a 1" rake.

I don't know how much sag you are getting? could you provide some measurements and let us know what your calling sag.

I do not use the airbags when towing! Infact I air them down as low as allowed per instructions. They are only used for when I'm hauling firewood/sheetrock or other heavy things in the bed.

If you plan on using bag/timbrens for tt I would really look more into your hitch setup. Go to a scale and see what you are missing.

Dont get me wrong I love the bags but don't think they will help your issue correctly. They will most likely mask an issue of an improperly set up wdh.

The set up is very crucial on the wdh because the rear is a little softer but once you get it write you will know it. It will ride very nice and be a much more comfortable ride. It took me about 6-7 outings before I was able to get everything right. Once i felt everything was right I then went to the scales to verify.

Terryallan wrote:

Bob Landry wrote:
I have read in a couple of places that the rear suspension on the 1500 Ram trucks is weak to begin with so they are probably good candidates for some type of supplemental support. There's no problem with using air bags or springs to level the truck, but the WD needs to be adjusted after the truck rear end height has been established, because the bags will affect the adjustment and throw the WD off.

IF you use the bags to level the Truck, while hooked up. How will you know IF the WDH is doing any thing?????. You don't. . But using them before you hookup would work.

The instructions for adjusting the hitch on a vehicle with air ride, which is pretty much the same as bags, Goes like this. Go to a level spot. Unhook. Let the TV level itself. Turn the air ride / bags off. Adjust the hitch. Once it is done. Turn the air ride / bags back on.

I didn't say to level with the bags after the WD is hooked up. To do that changes the bar tension and you have no idea where you are with it.

One thing to remember when using airbags. They will unload the WD system when you air them up to level the truck. I use mine to level the X, but i also use them to fine tune the WD. I have to vary my air bag psi by 20psi to get the same ride coming home. That is because alot of things get used that i keep in the front area of the trailer and some such as dirty clothes get moved to the rear. So this can mess with tongue weight. For me they are more of a tool than a reason to level the X.

Bob Landry wrote:
I have read in a couple of places that the rear suspension on the 1500 Ram trucks is weak to begin with so they are probably good candidates for some type of supplemental support. There's no problem with using air bags or springs to level the truck, but the WD needs to be adjusted after the truck rear end height has been established, because the bags will affect the adjustment and throw the WD off.

IF you use the bags to level the Truck, while hooked up. How will you know IF the WDH is doing any thing?????. You don't. . But using them before you hookup would work.

The instructions for adjusting the hitch on a vehicle with air ride, which is pretty much the same as bags, Goes like this. Go to a level spot. Unhook. Let the TV level itself. Turn the air ride / bags off. Adjust the hitch. Once it is done. Turn the air ride / bags back on.

I have read in a couple of places that the rear suspension on the 1500 Ram trucks is weak to begin with so they are probably good candidates for some type of supplemental support. There's no problem with using air bags or springs to level the truck, but the WD needs to be adjusted after the truck rear end height has been established, because the bags will affect the adjustment and throw the WD off.

It's supposed to sag, or at least the rear should drop. In my experience, about 1.5" in about the max for a half ton and a properly adjusted WDH.

Focus on the front axle height/weight, returning to unhitched height/weight. Once you have that and the TT level to slightly nose down, you can measure the rear of the truck. If it's more than 1.5:, you are probably overloaded. Air bags will mask that. But the 2009+ Ram 1500 has pretty low payloads. A family of 4-5 in the cab can leave less than 600 pounds of loaded tongue weight.

Bob Landry wrote:

Wishbone51 wrote:

Bob Landry wrote:
Secondly, ignore advice telling you to crank on the bars until the truck is level. In spite of what you are going to read from a lot of members here, the purpose of WD is not to level the truck, it's to return weight to the steering axle. Go to the towing section and memorize the stickies on how WD works, and the other one on how to set it up.

If the front is pointing up, I don't see that how the weight could be effectively transferred to the front wheels.

You don't know until you either weigh the front axle before and after hitching up or by measuring fender height. Almost every truck is going to sag in the rear when hitched. WD is not meant to correct that. Nowhere in any truck owner's manual or in any hitch installation/adjustment instructions are you going to read anything about using the hitch to level the TV.

Yep. IF the front is pointing up. Weight HAS been removed from the front axle. All the air bags in the world, won't put it back. But a WDH will. As I said. Use the WDH to get the front back down. The rear will take care of itself. And that does not mean it will be back up to the unhooked height. It may still be down an inch or so. But with the front down where it should be. Steering control will be returned.

Thanks for all the help. I just watched the video and it's much more informative than the installation instructions. I am not taking the TT anywhere until Labor Day weekend. Between then and now I am going to load the truck up and set it all up according to the video. I'll let you know how I make out. Tim C