First off, let me say that I have searched through the forums….and I’ve found some good info on this topic, but nothing really concrete. And a lot of the info I found was from way back in the early 2000’s….but who know, maybe the answers are the same. I’ve got a properly set up WD hitch on my Dodge Ram 1500 that I use for towing my 19ft Zinger camper (4,400lbs loaded). It tows good, but I do get a good amount of wallowing/bouncing in the rear of the truck when hitting bumpy sections of highway. The shocks on the truck are good, so I think it’s just the soft factory leaf springs. I recently installed a set of firestone airbags on the rear axle of the truck, allowing me to adjust pressure as needed with the small compressor the kit comes with. Our first trip towing the camper after adding the air bags went great……I put about 20psi of air in the bags, and it made for a much firmer and more controlled ride. No more bouncing, it had a much more solid feel when towing. The only question I have is that with 20psi in the air bags, it will raise the bed of my truck a little bit….throwing off the “proper” measurements for how my WD hitch should be set up. I’m wondering if I could run one more link of chain on each bar of the WD hitch to get the bed back down to the proper height….or will that in turn take too much weight off of the front of the truck?I will say one thing for sure…….that one time I towed the camper with 20psi in the air bags and no other changes to the WD adjustements….it towed great. It’s not that I need the airbags for load capacity…..it just tows so much better ,and has a more solid feel with a little air pressure in the bags. Any thoughts? Info? Tips?

I bet if you remove your bars and have 20 on the bags you will find you don't even need the wdh.

Toddupton wrote:I bet if you remove your bars and have 20 on the bags you will find you don't even need the wdh.But isn't the point of the WD hitch to put added/needed weight on the front wheels of your truck??

The two items will be working against each other! I would never recommend to someone to install airbags on a bumper pull. Install them for a 5th wheel since that weight is in the bed of the truck and you can level it with the bags. Bumper pulls use a wdh to, for the ease of explaining, balance the load between the front tires and the back. For your small trailer you could just use airbags or wdh but not both. If I had to choose one it would be a wdh and zero out the bags.

Toddupton wrote:The two items will be working against each other! I would never recommend to someone to install airbags on a bumper pull. Install them for a 5th wheel since that weight is in the bed of the truck and you can level it with the bags. Bumper pulls use a wdh to, for the ease of explaining, balance the load between the front tires and the back. For your small trailer you could just use airbags or wdh but not both. If I had to choose one it would be a wdh and zero out the bags.How do the airbags work against the WD hitch? Don't the air bags in effect just increase your rear spring rate? How does that counteract the WD hitch?

Go look at etrailer.com they explain it better than me.

Using Firestone airbags with WD hitch? | Good Sam Community

14 Replies

imq707s
Explorer
May 03, 2017
I'm sensing some sarcasm here :)

I do know that without a WDH or without the air bags inflated....just hooking up the trailer to the hitch on my truck will squat the rear several inches....and makes the front end feel really light and sketchy on the highway. A WDH makes a huge difference in how the thing tows...the addition of air bags helped even more. That being said....I tow my 25ft / 5000lb skiboat straight on the hitch with no special wdh or sway control.....and it tows just fine.

But....you have to remember that a travel trailer (at least mine) usually has a full 40 gallon fresh water tank in the front....plus a bunch of gear. I guarantee that the tonque weight on my 19ft travel trailer is double (if not more) than the tonque weight of my 25ft boat.
Grit_dog
Navigator II
May 03, 2017
imq707s wrote:
Toddupton wrote:
I bet if you remove your bars and have 20 on the bags you will find you don't even need the wdh.

But isn't the point of the WD hitch to put added/needed weight on the front wheels of your truck??

Absolutely!! A 4400lb trailer will have the front tires dangling in the air as soon as that massive tongue weight is dropped on the hitch. In fact, without it, wheelie bars and straight roads only are necessary.......
Grit_dog
Navigator II
May 03, 2017
Toddupton wrote:
I bet if you remove your bars and have 20 on the bags you will find you don't even need the wdh.

Shame on you, lol.
Dontcha know that ANY "travel trailer" regardless of configuration, weight or tow vehicle capacity REQUIRES a wdh before the operator can even plan a trip with said trailer?
Those are rvnet rules. TTs are special/magical compared to other trailers and as such require the tender loving application of a wdh with sway control. Preferably pro pride or somthin or other brand, not them cheap ones with the manual knutzen valves. Those are junk and you won't be allowed in any campgrounds or RV parks but you'll likely crash and burn ina firey accident killing a bus load of choir children on their way home from singing at another irresponsible RVers funeral......who didn't use a wdh and attempted to tow a trailer bigger than a pop up without a dually!!
RinconVTR
Explorer
May 02, 2017
I have the same exact situation with Firestone bags and WDH.

The bags are not for leveling, I use them for added spring rate to reduce how far the rear wallows. Its the same as adding a helper spring.

The bags and WDH do NOT work against each other. The WDH transfers weight, the bags do not, and you want the front end to the original ride height or weight for best performance.

A little added height from the bags may throw off your WDH ride height measurements by a fraction, but who cares?

I would not recommend changing your set up at all.

You have the WDH set properly and the bags are simply adding a little spring "stiffness" to the rear end and you enjoy the way it handles. That's what matters most of all.
CKNSLS
Explorer
May 02, 2017
Sounds like an ill-adjusted WD hitch. You shouldn't need any supplemental airbags towing a trailer that small if your WD hitch is set up properly.
burningman
Explorer II
May 02, 2017
Durb wrote:
I towed a 6,000# trailer with a 1/2 ton truck. I adjusted the WDH so that the ball was 1" low from unloaded height. I then aired up the bags so the truck raised the 1" back to unloaded height, no more. This was about 20 lbs of air pressure. Admirable tow.

I was following my son and his trailer was all over the place. He had onboard air with dash control. He said he couldn't understand it as his bags were almost on max. We took off a link on his WDH and lowered is bag pressure considerably which improved his tow to good. By raising bag pressure he was unloading his WDH and anti-sway. He also created a hard fulcrum of his rear axle and the trailer weight was unloading his steering axle.

Bags are good when dialed in properly but create problems when over aired.

That's not an airbag problem that's a user error problem.
You have to set your WDH properly with the bags aired up.
If you set the hitch at static no-air height, then add air and change the static height, of course you'll screw up the original setting.
Air the bags, THEN set the bars. Keep adjusting until you find the right balance between the two.
Durb
Explorer
May 02, 2017
I towed a 6,000# trailer with a 1/2 ton truck. I adjusted the WDH so that the ball was 1" low from unloaded height. I then aired up the bags so the truck raised the 1" back to unloaded height, no more. This was about 20 lbs of air pressure. Admirable tow.

I was following my son and his trailer was all over the place. He had onboard air with dash control. He said he couldn't understand it as his bags were almost on max. We took off a link on his WDH and lowered is bag pressure considerably which improved his tow to good. By raising bag pressure he was unloading his WDH and anti-sway. He also created a hard fulcrum of his rear axle and the trailer weight was unloading his steering axle.

Bags are good when dialed in properly but create problems when over aired.
Terryallan
Explorer II
May 02, 2017
imq707s wrote:
Toddupton wrote:
The two items will be working against each other! I would never recommend to someone to install airbags on a bumper pull. Install them for a 5th wheel since that weight is in the bed of the truck and you can level it with the bags. Bumper pulls use a wdh to, for the ease of explaining, balance the load between the front tires and the back. For your small trailer you could just use airbags or wdh but not both. If I had to choose one it would be a wdh and zero out the bags.

How do the airbags work against the WD hitch? Don't the air bags in effect just increase your rear spring rate? How does that counteract the WD hitch?

When you raise the rear of the truck with the air bags it does indeed change the effect of the hitch. Raising the rear with bags will reduce the amount of weight transferred to the front axle.

Best thing. Go to a level place. Raise the ball off the hitch. Air up to the PSI you want. Measure the front bumper distance from the ground. Drop the TT back onto the ball. Measure again. attach the bars, and adjust adjust the hitch until you have returned at least 1/2 of the raised distance back down. example. IF the front bumper is 15 inches off the ground unhooked, and when you drop the ball on the hitch it raises to 17" You would want the bumper to drop back down to at least 16" to the ground. 15 1/2 would be good, 16 1/2 not so good.

Now. Here is the kicker. Be sure you don't raise the rear higher than it was unhooked But usually, IF you get the front right. The rear will take care of itself
badsix
Explorer
May 01, 2017
I would try and reduce the air pressure a few lbs. at a time and see what happens. do you have the air bags plumbed together or separate let us, me know what you do as i'm thinking about going to some air bags also. ps if it tows good with the 20 psi don't screw with it drive it. I've only towed mine a couple times so far but I get the same bounce. I've been looking at trailer shocks also there cheep and would keep the trailer from bouncing all over the place when towing over not so smooth roads.
Jay D.
Toddupton
Explorer
May 01, 2017
Go look at etrailer.com they explain it better than me.