Air Bag Helper Spring Pressure w/ Weight Distribution Hitch Towing

[mikefos]

Hi,

I have recently had installed Firestone (including Airlift for keyword search purposes) air bag helper springs on my 05 SR5 2WD V8, factory tow package. I tow a 2010 26' Jay Flight FB23 travel trailer (dry weight 4400#, loaded max weight 6000#, estimated loaded weight for us is 5000#). I use a Pro Series SC weight distribution hitch with friction sway control included. The air bags were installed to remove rear-end sag from the weight of the trailer. I was wondering at what PSI folks with a similar towing setup use? I want enough PSI to remove sag but not so much as to negatively affect the weight distribution and sway control provided by the hitch system (if that's even a valid concern).

Thanks,

Mike

 

[davem]

i have the air ride on my 04 sport and only pull a 6x12 utility trailer with a couple of quads and gear and inflate my bags to 10 psi and have no sag. my suggestion is hook up your trailer and play with psi in bags. go for a couple short hops with various amounts of pressure. every bodys set ups are goin to be different just goin to take a little trial and error. good luck.

 

[TechWrench]

Hi,

I have recently had installed Firestone (including Airlift for keyword search purposes) air bag helper springs on my 05 SR5 2WD V8, factory tow package. I tow a 2010 26' Jay Flight FB23 travel trailer (dry weight 4400#, loaded max weight 6000#, estimated loaded weight for us is 5000#). I use a Pro Series SC weight distribution hitch with friction sway control included. The air bags were installed to remove rear-end sag from the weight of the trailer. I was wondering at what PSI folks with a similar towing setup use? I want enough PSI to remove sag but not so much as to negatively affect the weight distribution and sway control provided by the hitch system (if that's even a valid concern).

Thanks,

Mike

I would check with the manufacturer of your W/D hitch and see what they recommend for its initial setup procedure. I have an equalizer W/D system, and as I recall, the setup instructions specifically request that you disable the air-bag suspension system for the initial hitch setup.

 

[mikefos]

I would check with the manufacturer of your W/D hitch and see what they recommend for its initial setup procedure. I have an equalizer W/D system, and as I recall, the setup instructions specifically request that you disable the air-bag suspension system for the initial hitch setup.

My hitch is very similar to an Equalizer. By initial setup procedure, do you mean when hitching up the trailer for travel (and then inflating the air bags), or do you mean when (in my case) the dealer shop installed the hitch, installed the brake controller, and we took it for a spin to make sure everything was adjusted and ok? The air bags were not on the tow vehicle when the hitch was installed and the trailer checked out.

Thanks,

Mike

 

[scottm]

I would check with the manufacturer of your W/D hitch and see what they recommend for its initial setup procedure. I have an equalizer W/D system, and as I recall, the setup instructions specifically request that you disable the air-bag suspension system for the initial hitch setup.

I think the concern there is that an auto-levelling air suspension would keep trying to compensate for anything you do with the hitch during setup.

My brother and I ran AirLift bags in our 80-series Land Cruisers, similar in size and weight to your 4R. I towed a fair-sized construction trailer every day for work, he occasionally towed an over 6,000-lb car hauler cross-country, both on stock hitches. The bags are great for towing, make a huge difference in stability, the more pressure the better. I regularly ran full 30psi or more. It was especially nice with seven occupants and a heavily loaded roof box, no sag and no sway. Your brakes are probably the bigger concern, even with trailer brakes, just be careful.

 

[TechWrench]

My hitch is very similar to an Equalizer. By initial setup procedure, do you mean when hitching up the trailer for travel (and then inflating the air bags), or do you mean when (in my case) the dealer shop installed the hitch, installed the brake controller, and we took it for a spin to make sure everything was adjusted and ok? The air bags were not on the tow vehicle when the hitch was installed and the trailer checked out.

Thanks,

Mike

The issue is with the final ride height of the tow vehicle, and how the W/D hitch was initially adjusted to maintain a level (as possible) final position on the towed vehicle (trailer). If the W/D hitch was installed, and adjusted properly, the trailer should ride as close to level as possible. This final adjustment will take into account the amount of depression (sag) the rear of the tow vehicle experiences when the full tongue weight of the trailer is applied to the hitch. If, you now use a set of rear air bags to raise the rear of the tow vehicle in order to bring it back to the original ride height before the trailer was connected, you will change the level on the trailer, which might affect how it handles. I am not saying you can't use the air bag system, but you may have to adjust the height of the ball on the hitch lower so the trailer will still ride level. You may also have to adjust the amount of tension on the W/D hitch spring bars so you will still achieve the correct amount of weight transfer to the front axle of the tow vehicle. The dynamics of how a W/D hitch system is supposed to work is not that complicated, but it can take some time to understand, and if the hitch is not adjusted properly, it can adversely affect the final results, and may cause towing control difficulties.

 

[jetboy1975]

The whole idea of the weight distribution hitch is to transfer weight from the rear to the front of the vehicle thereby reducing sag at the same time. If it still sags (more than an inch or so) enough to need bags to level then it's not set up properly. I would reset it without airbags so truck and trailer are within an inch of level and then pressure the bags enough to get rid of the last bit of sag.

Just for comparison I have an '04 Limited with factory bags and a 4000lb trailer. I disable the bags in level position and then hookup. Truck and trailer are perfectly level with the wdh setup. When I enable the bags again it doesn't even adjust.