WDH Set-Up with New Airbags

[BigDinMB]

I'm seeking guidance/ideas on how to alter the setup my existing Equalizer WDH, after I install Airlift 5000 Ultimate airbags on my 2021 Chevy Silverado 2500 Duramax.
I tried searching, but didn't find any posts that address my issue.
Currently, my 2021 2670MK tows fine--no sway issues, rides level, tires wear evenly--EXCEPT for severe porpoising/bouncing on bad roads, highway expansion joints, bridges, etc.
So, I'm adding airbags to help with that.
I'm not sure of how to best adjust hitch setup to account for the airbags. Leave hitch setup alone and just inflate airbags enough to lift rear very slightly? Hitch camper without WDH bars, inflate airbags till level and then add hitch bars back in?
Just unsure of the order to do things once airbags are installed.
TIA for helpful feedback and Happy Camping to all!

 

[Capt Bob]

Well I don’t have your size trailer or as front heavy as your TV, but I have experienced porpoising with our MLE on both the 1500 we first towed with and to some degree our 2500HD. The 2500 was definitely less but at times, noticeable.
We run the infamous Blue Ox Sway Pro WDH which has been touted on You Tube as subject to porpoising. I countered that by running 25 psi in the bags on the 1500. Problem solved. I did not change the hitch setup because everything else worked very well.

I have experimented with the psi on the 2500. I did lower the hitch height when we first switched TVs due to the much higher rear height and the stiffer springs. It didn’t settle down like the 1500. Once I had the height where I wanted, I started playing around with the bags. Our last tow was at 18 psi and that kept the trailer level. I’m going to add more for our next trip in July. I can still lower the hitch height another inch if need be so…..

My suggestion is to add some air and see how it affects the ride before changing your hitch setup.

 

[BigDinMB]

Thanks! I'll likely try your suggestion before changing my hitch. Have a good one.

 

[JPS350]

You don't alter the hitch setup to account for the airbags. Set up your hitch to take out the amount of rise in the front that you want to take out with the air bags out of the picture (5 psi or so in them). I take it all out and a little bit more if possible to balance the weight forward. Then air up the airbags just enough to stiffen things up in the rear a bit. You may only need 15-20 psi or so. Don't add enough to raise the rear. Your hitch should take care of most of the sag. Adjust the airbags for the ride you want from there.

Also, not sure how you set your airbags up, but I would set them up separately side to side so one side can't affect the other.

 

[Riverbug]

The actual correct way to set up the hitch with air bags is to first set the air bags with the PSI you want to run at. Then you go through the installation process for the hitch. If you change the air bags PSI, then the installation process should be done again. I used to alter the air bags based on various trailers or loads, but I always set the air bags to 40PSI before hooking up to the RV. That was just my preferred setting.

 

[BigDinMB]

Thx! Just ordered the airbags; haven't received them yet. Hopefully installing them next week. My current hitch setup works well, except for the porpoising problem. I set it up per Equalizer's install procedure and specs, and weight distribution and leveling of both truck and trailer are good. On good road and weather conditions, I can comfortably cruise at 70 mph. It's mainly when I encounter road expansion joints, like the route 22 bridge coming into Myrtle Beach, that the bouncing becomes borderline scary, even at 45 mph.

 

[JPS350]

The actual correct way to set up the hitch with air bags is to first set the air bags with the PSI you want to run at. Then you go through the installation process for the hitch. If you change the air bags PSI, then the installation process should be done again. I used to alter the air bags based on various trailers or loads, but I always set the air bags to 40PSI before hooking up to the RV. That was just my preferred setting.

Disagree, but here's my take. The hitch controls the weight distribution, sag and front end weight unloading and needs to be set up first. The airbags help with the ride and you shouldn't need to adjust them to raise the rear of a truck that's made to handle the load you're putting on it, just adjust them enough to give you the ride you want. So long as you do this nothing changes how the weight is distributed.

Interesting discussion of this in the link below, especially post #9.

https://www.gdrvowners.com/towing-and-hitches/9259-leveling-for-towing-a-315rlts

 

[Capt Bob]

Just to follow up on my original post, I set my hitch up to get the best towing experience concerning tracking, sway, and as close to level as possible. I had to tighten the bars more on the 1500 to put more weight on the nose but the 2500 doesn’t require as much. They ride one position less. This seems to give a slightly better ride without sacrificing sway control. The bags could change the rear height if I inflate them more than needed to reduce/eliminate the porpoising. They are only inflated to what gives the best ride quality. That can vary from trip to trip. The bags are really there to assist when I’m not towing but have a heavy load in the bed.

 

[BigDinMB]

Thanks to all for the info! Looking forward to having a smoother towing experience.

 

[Riverbug]

Disagree, but here's my take. The hitch controls the weight distribution, sag and front end weight unloading and needs to be set up first. The airbags help with the ride and you shouldn't need to adjust them to raise the rear of a truck that's made to handle the load you're putting on it, just adjust them enough to give you the ride you want. So long as you do this nothing changes how the weight is distributed.

Interesting discussion of this in the link below, especially post #9.

https://www.gdrvowners.com/towing-and-hitches/9259-leveling-for-towing-a-315rlts

You do you.

 

[RV2600RB]

Don’t ditch the hitch, it’s a good one.
Experimentation is the key.
Rich

 

[BigDinMB]

I agree! Bought mine in 2003, to use for towing my 2003 boat. Then, got extra brackets & related hardware for the camper frame and now use it for both. I've been pleased with the Equalizer's performance and durability.
Looking forward to installing Airlifts and figuring out what psi improves porpoising and then whether anything else needs to change.

 

[classicrockguy]

I’ve run airbags and WDH on my last 2 trucks for tt towing. Experimented with different configurations of the 2 working together. I find focusing on the WDH to get the “most” out of it, and then adding a bit of air to “stiffen things” works best for me.

I typically have 15-20psi in the bags after hitching (which is 7-10psi unloaded). This takes 750-1000lbs off of the springs when loaded. I use the CAT scale to confirm I still have a bit over 50% “weight recovery” at the front axle. Again, you have to work both systems to get to the combination you want.

Consider that when the suspension flexes the bags compress, and the pressure rises proportionately. Compressing the bags to half their volume over a hard bump doubles the pressure to 30-40psi, which means they get progressively stiffer to 1,500-2,000lbs. The truck springs are also progressive, especially if/when you hit the helper spring (if you have one).

I find if I run more initial pressure in the bags such that the rear of the truck is raised more, the WDH hitch is less effective and then has to also be stiffened. This degrades the whole driving experience by making the rear too stiff and the ride more “fidgety”.

Seems to me the WDH does the main work, and the bags are “season to taste”. At least that’s what works best for me. YMMV.

Previous post on my FS airbags install … post #6

https://www.mygrandrv.com/threads/air-springs-couple-of-questions.73046/

 

[TimtheToolMan]

How many miles on the truck--making sure the shocks are still good? How many of the miles were towing?

Was CAT scale used to setup hitch--returning truck front wheel weight, loaded vs unloaded to the same weight?

 

[BigDinMB]

About 52k miles on truck, roughly 4k towing, all with WDH. Did the hitch setup per Equalizer procedure (using height measurements). Have done the weigh-3-times at CAT scale several times and numbers seemed reasonable, except for once with full fresh tank when trailer was 525 lbs over. Tongue weight is usually around 1100 lbs. Trunk has the bed camper package and 6.6 Duramax and tends to be a pretty stiff ride. It's definitely time to purge some excess stuff/weight from the camper.

 

[classicrockguy]

How many miles on the truck--making sure the shocks are still good? How many of the miles were towing?

Was CAT scale used to setup hitch--returning truck front wheel weight, loaded vs unloaded to the same weight?

Not clear who your question is directed to. Both my previous F150 and my current F250 were nearly new when I bagged them. My F250 has 32,000miles after 3 years. About 1/2 towing. We also use it for long road trips without the trailer. Not too much “around town”, as HD diesel trucks suck for this.

I always use the CAT scale for WDH setup. I go for 50% weight recovery on the front axle per Ford recommendations. My current rig goes down the road nicely, but at 60’ total length it can be a handful to maneuver or stop quickly.

 

[TimtheToolMan]

My apologies (my mistake) @classicrockguy and thanks for the interesting information.

My question about miles and shocks was directed more to @BigDinMB . At 52k miles with a long TT, even though few were towing, and the ride instability, I would be tempted to consider Bilstein 4600.

 

[BigDinMB]

Thanks Tim. At this point, I've actually got several changes in the works over the next week or so; upgrading camper suspension with Roadmaster 5K Slipper Springs and matching shock absorber kit, Airlift airbags on the truck, and purging some excess weight from the camper.
After all that, I'll re-check the hitch setup, figure out airbag pressure settings, and test drive on known bouncy roads. Then I'll decide if I need more hitch or airbag adjustments and whether new truck shocks might be needed. Probably shouldn't add more variables to the mix yet, and hoping to give the budget a break for a while.