Airlift 5000 airbags and WDH

Ron, it was two years ago when I got the trailer new, just followed the instructions provided by Equalizer and watching video guides for suggestions. Driving the setup was pleasureable and confident, even the wife drives and says so, so I guess I'm assuming that it worked. I have not changed a thing since adding the airlifts, as I noted it just makes the ride on some roads MUCH more pleasureable.
Sorry, I couldn't tell you at 60 MPH whether there was any difference in rear-end height between the 25 and 60 PSI's.

As for TV axle loads at different PSI's, interesting propostion. Off-hand I can't imagine very much difference, but might be worth a try.
Regards, BGood

W.E.BGood wrote:
---The WDH was correctly set-up and adjusted for the trailer prior to the airbags being installed.

Thanks for the contribution.

How do you determine when the WDH is correctly set-up?

Did you notice if there was any change in the rear-end height when you had 60 psi in the bags versus 25 psi?

If you ever get the chance, it would be great if you could measure the TV's axle loads, with WD applied, for 5 psi in the bags and then for 60 psi.

Ron

brulaz wrote:
So, how about this. Pump up your air bags to some pre-determined level (say 10psi?). (Doesn't have to be level. My truck is permanently lifted by 1" in the rear because of the Roadmaster Active Suspension upgrade). Hitch up the trailer and adjust your WDH concentrating on returning weight to the front end (reducing front end lift). Check for improved handling. If you need more air to improve handling, do it, but then (if I understand this correctly) be prepared to add more tension to your WDH to counteract the additional upforce? Again, the objective is to reduce the front end lift, not the rear end sag. Repeat as necessary.

I agree 100%.

That's exactly what I've been advocating for several years.

Some example advice is given in this post:

If you feel it is necessary to use air bags in conjunction with a WDH, you should first add some air to the bags and then adjust the WDH.
If the rear of the TV still squats more than you like

{or you don't have enough air pressure for the desired "ride"}

,
add some more air and re-adjust the WDH. Repeat if necessary.

Ron

FWIW I'd like to contribute my just-finished "real life" experience.
TV='08 Tundra DC 4X4 w/AirLift 5000's & remote control.
TT=Keystone Outback 250RS (approx.7,200 loaded)w/Equalizer 1k/10K WDH.

I had the Airlifts installed for 2 reasons...help minimize the "harmonic porpoising" or "bucking" we encounter on some stretches of concrete-sectioned paved roads we have here in the midwest, and enable short-distance towing and improve tight parking manuvering without the WD bars installed. The WDH was correctly set-up and adjusted for the trailer prior to the airbags being installed.

Coming back from an outing yesterday, I drove 85 interstate miles Northbound against a constant 25-35 wind (gusts to 40+) from the NW to NNW, then 65 interstate miles Eastbound, same or even gustier winds. On some sections I ran 25 lbs. in the AirLifts, some up to 60 lbs. just to improve the ride. I had some pushing around of course, especially when passed by the semis going Ebnd, but my totally subjective, seat-of-the-pants evaluation is that it was very controllable, had no trouble staying in my lane, not "white-knuckled" at all, and not tired when we got home.

Regards, BGood

Ron Gratz wrote:

...
If, in fact, enough pressure can be added to improve handling without giving noticible lift, this process will give the desired WDH objective.
If there is noticible lift, then the WDH load transfer would be reduced.
If there is no noticible lift, the air bags do nothing to reduce the amount of rear-end sag.
Pick your poison.

goducks10 wrote:
1st, load truck with no TT hitched.
2nd, air bags up to restore truck rear hgt.
3rd, hitch up TT.
4th, adjust WD to transfer needed weight.
5th, go camping.

This is the second of the two posts.

This process will reduce the amount of rear-end sag and will satisfy the WDH objective.
It also has potential for improving handling because sufficient load has been transferred to the air bags to cause a noticible amount of lift.

Ron

*** Just trying to understand all this. ***

The last sentence implies that only when there is noticeable lift has sufficient load has been transferred to the air bags to improve handling.

From what I've heard, that's not correct. In a heavily loaded truck, or truck+trailer, a substantial amount of air pressure can be applied before there's any "noticeable" rear end lift, and the handling improves.

But it also occurs to me that even if this upforce is "unnoticeable" won't it also reduce the WDH load transfer? Same as you say for a "noticeable" rear end lift via air bags?

If so, we should be concentrating on front end lift (weight) instead of rear end lift (or lack of it).

So, how about this. Pump up your air bags to some pre-determined level (say 10psi?). (Doesn't have to be level. My truck is permanently lifted by 1" in the rear because of the Roadmaster Active Suspension upgrade). Hitch up the trailer and adjust your WDH concentrating on returning weight to the front end (reducing front end lift). Check for improved handling. If you need more air to improve handling, do it, but then (if I understand this correctly) be prepared to add more tension to your WDH to counteract the additional upforce? Again, the objective is to reduce the front end lift, not the rear end sag. Repeat as necessary.

AFAIK none of these rear end suspension mods will have much effect on the front end. That's where the WDH comes in. And when adjusting the WDH, it's the front end we need to concentrate on.

brulaz wrote:
5 psi (250# upforce) is the baseline, zero lift with no WDH. Then with the WDH he adds another 5 psi (another 250#) before seeing any lift.

That's just an additional 250# upforce on the rear axle. With all the WDH upforce, I wouldn't expect much noticeable lift on a heavy TV handling a heavy tongue weight.

The approach seems reasonable to me. Adjust the WDH with the air bags un-inflated (or just inflated so no rear lift). To improve handling, add air until additional rear lift just barely noticeable. No?

RinconVTR wrote:
Last two posts....spot on.

The first of the "last two posts" is quoted above.

For something to be "spot on" the process needs to have a defined target.
Let assume the target of adjusting the WDH is to restore the front axle load to its unhitched value.
That typically leaves the rear of the TV 1-2" below its unhitched height.

A second target, after adjusting the WDH, seem to be to add enough air to the bags to "improve handling" withoug causing more than a "just barely noticible" amount of additional rear lift.
This second target presents a problem because nobody seems to be able or willing to say 1) how much air pressure is required to improve handling, and 2) how much additional rear lift will result.

If, in fact, enough pressure can be added to improve handling without giving noticible lift, this process will give the desired WDH objective.
If there is noticible lift, then the WDH load transfer would be reduced.
If there is no noticible lift, the air bags do nothing to reduce the amount of rear-end sag.
Pick your poison.

goducks10 wrote:
1st, load truck with no TT hitched.
2nd, air bags up to restore truck rear hgt.
3rd, hitch up TT.
4th, adjust WD to transfer needed weight.
5th, go camping.

This is the second of the two posts.

This process will reduce the amount of rear-end sag and will satisfy the WDH objective.
It also has potential for improving handling because sufficient load has been transferred to the air bags to cause a noticible amount of lift.

Ron

Last two posts....spot on.

1st, load truck with no TT hitched.
2nd, air bags up to restore truck rear hgt.
3rd, hitch up TT.
4th, adjust WD to transfer needed weight.
5th, go camping.

Ron Gratz wrote:

...

It sounds like you'll need to try this yourself to believe, but for the initial PSI put into the bags, I doubt most are getting any lift. In my case, I dont get lift while unloaded until I go over the minimum of 5psi. I found with WDH attached, I can easily add 10psi and not induce any extra lift. Again, the air bags with WDH are just adding spring rate at this point which translates into reduced suspension travel.

According to Firestone, "As a general rule, the air helper springs will support approximately 50 lbs. of load for each psi of inflation pressure (per pair)".
That suggests that, if you add and additional 10psi to each bag, you will add an additional approximately 500# of upward force against the chassis.
Are you saying this does not cause the rear of the TV to raise?

Ron

5 psi (250# upforce) is the baseline, zero lift with no WDH. Then with the WDH he adds another 5 psi (another 250#) before seeing any lift.

That's just an additional 250# upforce on the rear axle. With all the WDH upforce, I wouldn't expect much noticeable lift on a heavy TV handling a heavy tongue weight.

The approach seems reasonable to me. Adjust the WDH with the air bags un-inflated (or just inflated so no rear lift). To improve handling, add air until additional rear lift just barely noticeable. No?

I try to apply common sense to things which require the use of common sense.

For things which follow the laws of physics, I try to apply the laws of physics.

Common sense is what tells us the earth is flat and the sun goes around it.
The laws of physics tell us otherwise.

Ron