Airbags VS. WDH?

UNSTUCK

But stuck more often.
Boy did I jump/fall down a rabbit hole. Not sure I even want to bring this up on here, but I trust you guys more than the random internet. I have literally found every possible answer to this question, and every possible way of setting up the trailer. I have no idea which one is right.

I have a 2021 GMC 1500 with 6.2L, 10 speed, max tow package. It's rated for 11300 towing, 1700 payload and 1100 tongue weight. I installed Timber Grove frame to axle airbags and then built my own auto leveling system. Viair air compressor, 2 gallon air tank. That feeds air to a single semi trailer airbag valve that adjusts air pressure based on the distance from the bottom of the truck bed to the top center of the rear axle.
This is the second truck I have ran with this same set up and it has towed my HEAVY boats flawlessly. My last boat weighing in at 9500 pounds, boat and triple axle trailer was a dream to pull with this GMC truck. Plenty of power and breaking. From what I've read, boats tend to be an easier pull than TTs or enclosed cargo trailers due to less side wall. Wind does not push them as much. I have been in very strong cross winds with the boats and they did fine. Never felt nervous. I've never used a WDH for the boats or the car/Jeep hauler.

I just purchased a 24' enclosed trailer. 10k GVW. 4700 empty weight. 5300 payload capacity. The goal is to eventually haul our household stuff to Alaska, but may see some travel to Arizona before that.

So, some say I still need to run a WDH with my airbags. Some say I don't. The ones that say I need the WDH say set up is critical, but there are a few contradicting ways to set them up. Adjust bags to right height first, then do WDH. Set the WDH first then level as needed with bags. Get bags level, note the PSI. Drain bags, set up WDH then go back to that PSI in the bags........(head exploding).

I emailed Steve at Timber Grove. Good guy. We have spoke several times. He told me the bags are all that's needed, but I should add a sway control system. He just happen to have such a kit he put together for half ton trucks towing heavy. He quoted me that system:


The sway control only system makes sense to me. Level everything with the bags (automatically) and let that system take care of any sway.

Dare I ask your thoughts?

PS. I desperately need new, stiffer shocks for this truck. The Cadillac floating is too much for me, and worse when towing. Does Falcon make a tow mode shock for this truck like they do for the Ram? Any other recommendations?
 

boogie_4wheel

Active Member
My toyhauler has a 1000lb tongue weight. I brought it home with a late 90s half ton without using a WDH. The front floated. I bought an Equalizer 4-Way and set it up so that my front axle weight was the same when connected to the trailer as it was without the trailer. There was a very slight push in the wind or passing semis causing the trailer to yaw. It honestly drove really well.

I now pull it with an 8 lug diesel, longer wheelbase, much more front axle weight, spring capacity, yada yada. I set it up the same way. Even without the distribution the front end weighs more than if it was optioned with the gas engine. I still use the WDH because it helps with porposing on frost heaves, bridge transitions, ect. Being the 4-way (built in sway assist) it does still help from being pushed around.

For your setup, I'd let the bags level automatically. Focus strictly on returning the trucks front axle weight/ride height.
 

zmotorsports

Hardcore Gearhead
Vendor
Location
West Haven, UT
Personally, I always preferred to run Weight Distributing Hitches (WHD) over air bags. I tried the air bags under my old Ford F-250 extended cab long bed (yes, I owned a Ford at one time in :rolleyes: ) and although they helped with our 8500-pound 24' enclosed race trailer when I was towing, the ride was horrible when I was not towing. The bags only needed to have about 5 or 10 psi in them when not loaded but it was enough that the ride went right out the window when running empty. When towing and the air bags at around 34-36 PSI (where I found they leveled and assisted the best) the truck road well and seemed to handle crosswinds well. My complaint was under heavy braking it was still transferring enough weight that the front end would get light as the weight pushed down on the rear as it was transferring forward.

I decided to remove the air bags and give a WDH hitch a try and it made a huge difference. It loaded the front end more evenly and definitely helped during those hard braking occasions where the truck stayed more level and I could tell the front brakes were contributing more than with the air bags.

When we sold that truck and I built my Big Block powered 3/4 tone Suburban I kept the WDH and continued to use it with our 24' enclosed trailer. We then ordered a new 26' Haulmark Edge race trailer and loaded it was over 12k pounds but still handled great with the WDH. With our current 2006 2500HD Duramax I had to modify the WDH for the drop necessary to compensate for the lift height of the truck but the same results with towing an even heavier enclosed trailer.

My son purchased his 2002 2500HD Duramax and it had air bags under it but we removed them as the ride was terrible and he too uses a WDH when needed.

This has just been my personal experience but I have been using WDH's since the early 90's now and have had very good results with weight transfer, braking and sway control in even heavy crosswinds. I even have used a WDH behind behind our last 3 coaches with the same results.
 

UNSTUCK

But stuck more often.
I'm not ready to ditch the air bags, as I see more boats in our future and I think they are the best solution for them. I agree the bags make the truck drive a bit worse when not loaded. I'll take that trade off as it drives so much better when loaded.
 

N-Smooth

Smooth Gang Founding Member
Location
UT
Only thing I can guarantee is that you won’t put an equalizer on there and be like “wow, this sucks”

They really help with halfies, especially towing camp trailers or enclosed trailers.
 

frieed

Jeepless in Draper
Supporting Member
Location
Draper, UT
For the soft suspension on my F-150 I ran both. WDH will transfer some of the tongue weight back onto the front wheels of the tow vehicle which is better for steering and onto the the back wheels of a tandem axle trailer which evens out the tire wear. I ran my travel trailer with both a WDH and airbags since added crap (generator, firewood, etc) in the truck bed still made it squat. Level it out with WDH with an empty bed (you want the trailer a little bit nose down and the truck only an inch or so higher in front) then load the bed and level again with airbags.
Also, big thumbs up for Equal-I-Zer brand hitches.
 
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Corban_White

Well-Known Member
Location
Payson, AZ
I like the WDH for the reasons listed, mainly the transfer of the weight back onto the front axle. I have a bunch of numbers if you're interested (I like to weigh my setups to know what I'm running) but the gist of it is heavy tongues cause the truck to pivot around the rear axle. Air bags can even make this worse. They are great for fifth wheel/gooseneck hitches and extra cargo though. The way I would set yours up is load the truck and trailer, let the auto level do its thing with the truck loaded but without the trailer hooked up. Measure from the road to a known point on the front fender. Hook up the trailer without the WDH and wait for the auto level to do its thing. Measure from the ground to the same point on the front fender. Then adjust the WDH until that distance to the front fender is close to halfway between the loaded and unloaded number. Drive and tweak for "feel".
 

UNSTUCK

But stuck more often.
My biggest fear, I guess, is the WDH spreads the load so much that I don't get enough pressure in the bags to prevent bottoming out. The truck is so light in the back end that more than a couple PSI starts lifting it. I had to remove the bump stops to fit the bags and driving around empty can cause a lot of bottoming out. That's where I'm hoping new, stiffer shocks would help out.

I put an Equal-I-Zer in my amazon cart. Just waiting to hear back from them about my airbag situation and their recommendation.
 

UNSTUCK

But stuck more often.
I got a response from Equal-I-Zer tech support. Left a little to be desired:

"When the customer has air bags we have seen the best performance out of our hitch when the airbags are set to 20 ft-lbs and then you set the hitch up after it is inflated.
Let me know if you have any other questions."

I assume he meant 20 PSI. I'd max the bags out in my truck at 20psi. I've read numbers from 30-40psi for guys running heavy loads. I can't believe they would recommend a set number. I specifically told them I have an automatic system and have no idea what my pressures are. :(
 

str8axleguy

Registered User
Location
Ogden, UT
I run up to 80 or 90 psi in mine when hauling my fifth wheel travel trailer, it’s around 12k loaded up and sometimes I pull doubles. Not sure how many ft-lbs. that is tho lol!
 

Gravy

Ant Anstead of Dirtbikes
Supporting Member
I installed a set on my buddy's f-150 that required removal of the stock bumpstop that sits on top of the leaf spring between it and the frame. I want to say they were Firestone bags (the kit was some other brand like RideRite maybe?). At full flex the bag smashed and twisted and it tore on the side. It was a bad deal since he was planning hauling his truck bed camper off the mountain when we reached his property up top.
I replaced the bag and built a standoff on the inside of the frame rail and used an Isuzu Rodeo/ Honda Passport foam bumpstop to keep it from happening again.
In my experience bags don't like full compression empty also being stretched rips them too. At the same time we ended up building a bucket the bag could land in so we didn't have to hard mount it at the bottom.

If you never went full extension I wouldn't bother with the bucket.
 

jackjoh

Jack - KC6NAR
Supporting Member
Location
Riverton, UT
Get rid of all the added stuff and just use the WDH. Used properly it will do the best job for your rig as it did mine.
 
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