Air bag effects on axle weights, finally solved (for my rig)

Discussion in 'Tow Vehicles, Hitch & Towing' started by Rusty2192, Jun 9, 2019.

  1. Rusty2192

    Rusty2192 Well-Known Member

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    I swung by a CAT scale on my way to the campground last Thursday. I was curious what all of my weights were and I was really curious to see what difference the airbags make on the front axle, so I threw the bike pump and pressure gauge in the TV too. The TV was loaded down pretty typically, which means way too much junk ;) I tried to put the heaviest stuff (EZ Up, cast iron Dutch ovens, propane fire pit, etc) as far forward as possible though there was still some heavy stuff at the back too like a cooler.

    Here are the results:

    5DD61F8D-A8EA-405E-8245-F22E32701747.jpeg
    Total trailer weight:1,900 lbs
    Tongue weight: 280 lbs

    The air bags made absolutely no change to the front axle with my setup (each rig is different, so this can’t be automatically assumed for any other combo). To be clear, I wasn’t expecting them to transfer weight to the front like a WDH, I was just curious how much, if any, they removed from the front. Turns out it’s none at all. Interestingly, they actually shifted 20 pounds off the rear axle onto the pup. My guess is that it’s just due to the change in hitch height.

    A few observations: I’m just about maxed out on the pup’s GVWR. If I ever go much larger I’m going to need to use a WDH to shift some weight from the back to the front axle as it’s already close to the 3,100 lb axle rating. I drove the 10 miles or so to the scale with the airbags deflated and I had forgotten just how much they help and not just the sag. The stiffer rear end behaves so much better.

    As a side note, the Weight My Truck app for the CAT scales is awesome. Just pull onto the scale and the app should have the location from gps. Tap weigh, wait the the person inside the building to do their thing, and off you go. It shows the weights right away and emails a PDF. It automatically charges your payment source on record (I did PayPal). First weigh is $11 and each reweigh within 24 hours is only $2.
     
    Last edited: Jun 9, 2019
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  2. bheff

    bheff Well-Known Member

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    I'm thinking about getting airbags for my vehicle. While I'm not concerned about weight transfer, I do want to keep the sag to minimum. I may go ahead pull the trigger since you said they help with the ride and squat.
     
  3. gec66

    gec66 Active Member

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    Exactly as expected. If you need to move weight around it has to be done with loading or a WDH, if your camper and TV are allowed to use a WDH.
     
  4. Rusty2192

    Rusty2192 Well-Known Member

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    Not quite exactly as expected, airbags can actually remove weight from the front axle, which is one reason why some people argue against them. A WDH manufacturer has a video demonstrating this, but it’s with something like 1,000 lbs tongue weight on a full size truck. A pop up on a TV with a short overhang just doesn’t have enough leverage to do too much.

    Maybe I’ll swing by again some day with an empty TV to see if the gear I had loaded in the TV in front of the rear axle helped hold down the front.

    They are great for that. Depending on the vehicle they can be really easy to install too. They aren’t a substitute for a WDH, but if everything is already in spec, they are a huge help to stiffen up the rear suspension. I also like that I can deflate them when towing to go back to stock stiffness. I’m sure my wife and kids really appreciate that as it’s her daily driver.
     
  5. Spridle

    Spridle Active Member

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    So no real weight change, which I would not expect. But obvious added control by essentially upping the rear spring rate. Love the way the data is displayed.
     
  6. Kettlebelle

    Kettlebelle Member

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    Nice data! I’m just curious what your tow vehicle is? I’m on my phone; apologies if this is visible somewhere, I can’t see it.
     
  7. Rusty2192

    Rusty2192 Well-Known Member

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    2016 Sienna with Airlift 1000s
     
  8. NavarWynn

    NavarWynn Member

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    When we've got significant tow weight on the Odyssey, the sag is bad, and that definitely impacts the FWD traction. Now obv. the pup isn't anywhere near the GVWR, but with kids, dogs, gear (and more gear) - the load affects driveability, I was planning on putting Airlifts on it - and hopefully improving the overall balance because it's kind of embarrassing to pull away from a stoplight pointing up a hill sounding like you are 18 doing a burnout *rolling eyes*.
     
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  9. MNTCamper

    MNTCamper Active Member

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    Airlifts work good on the Ody. Just pulled a 5K mile trip with them on my '07 and we were super loaded up, but they worked well, ran them at 30 psi.
     
  10. Orchid

    Orchid Sharp Shootin' Grandma

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    We have air bags on our Odyssey and they never worked right. Found out today, while installing bump stops, that was due to shoddy installation.

    No real shocker considering who I had put them on for me.

    I use the CAT scale app as well. I love it! So easy, never even have to get out of the car.
     
  11. JimmyM

    JimmyM Well-Known Member

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    Air bags won't put weight back on the front tires. Only a WDH can do that.
     
  12. kennedyma

    kennedyma Member

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    Put air bags in my Jeep Wrangler Unlimited. Best mod I’ve made yet to help towing.

    My trailer is only 1,850 dry so I’m well under what I can tow. The bags make a ton of difference in how it sits.
     
  13. silverfz

    silverfz Active Member

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    Airbags is not for WDH.
    I initially set the Airbags to 20 PSI and then then setup the WDH. the airbags act more like springs to hold weight and suspension to provide tires more traction.
     

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