Air Lift as a Substitute for WDH?

[Thunderchicken]

I've searched for this and haven't come up with anything that addresses it. I have an `09 F-150 with the trailer towing package. I've never towed with this vehicle before and plan on towing a 6000# trailer. IMO the rear springs are pretty soft till you hit the overloads. I'm adding a set of Air Lift 5000s. (Would have done anyway for cargo reasons.) I intend to measure and weigh the rig before deciding. My question is, assuming I can level out the rig with the Air Lifts, what extra advantage would adding a WDH provide? TIA

[BulletOwner1]

Air bags will lift your rig but a WDH will actually transfer weight to the front of the pickup thus, if the hitch is put on properly, leveling out both rigs. In my case with the WDH my trailer ends up just about perfectly level with the truck slightly nose up. I am considering air bags to correct this. If you just use air bags your nose is still going to be lite and may result in control issues.

In short, WDH first, air bags second if needed. IMHO

[tech740]

I agree. A well set up WDH may make it so you don't need the airbags. It outs the weight on the front axle and some back on the trailer axles also. Your truck hitch is not rated for that kind weight without a WDH system either.

[bsmith0404]

Ditto...air bags do not transfer weight back to the front wheels, they just lift the back end up.

[Thunderchicken]

Originally Posted by bsmith0404

Ditto...air bags do not transfer weight back to the front wheels, they just lift the back end up.

Originally Posted by tech740

It outs the weight on the front axle and some back on the trailer axles also. Your truck hitch is not rated for that kind weight without a WDH system either.

Originally Posted by BulletOwner1

Air bags will lift your rig but a WDH will actually transfer weight to the front of the pickup thus,

Thank you all for the replies. If I understand the flow of force using a WDH, the front end loading looks like a byproduct of the rear end lift derived from the hitch springs shifting tongue weight back to the trailer.

Tech740, you make a good point about the hitch rating. My truck and I are separated and I'll have to look at either the hitch or the manual when I get it back. I'll bet I'm over the weight carrying capacity of the tongue.

Assuming that I do both the bags and the WDH, I'm thinking that I should set the hitch up and after that's done use the bags to return the rear to it's stock ride height. Does that sound right? Or could I put the WDH spring bars in too much of a bind? (Although considering normal jounce and rebound I doubt it.) Any thought on that? Thanks again.

[Bob Landry]

Instructions or advice telling you to level the truck with the WDH are wrong and by doing that you are overloading the front end. The only purpose of WD is to transfer weight back to the steering axle, nothing else. Air bags will reduce and probably reduce rear end squat.

If you use both, adjust the airbags for the desired height and inflate them that way every time. Changing the height of the rear changes the tension on the WD bars by changing the amount of tilt on the hitch ball.

[bsmith0404]

This is a pretty good article about how a WDH works. The main thing you are doing is correcting the pitch created when the rear of the truck squats and the nose of the trailer dips. The purpose of the WDH is to spread the weight of the nose of the trailer allowing each axle to take on some of the weight......weight distribution. Air bags simply raise the truck back up, but do not distribute the load.

http://auto.howstuffworks.com/auto-p...on-systems.htm

[Bob Landry]

The WD is not used to level either the truck or the trailer. The hitch instructions, or at least Reese's instructions, tell you to get the height of the hitch and the hitch ball within a certain spec. That gets it pretty close before you start the adjustment. Once the WD is adjusted to return the right amount of weight to the steering axle, you can change the angle/level of the trailer by moving the hitch head up or down in the shank. This is going to let you get the trailer leveled without changing the WD adjustment because you are not changing the angle of the ball, just the height of the whole assembly. If the WD levels the truck in the process, that's just a side bonus, but it's unlikely that is going to happen unless the bars are adjusted too tightly. I think that if you see the truck is sitting level after doing the WD adjustment, something is wrong and you need to reassess the installation.

The reason for adjusting the hitch and THEN doing the air bags is that when you raise the rear of the truck, that is essentially tilting the ball towards the front which reduces the amount of tension on the bars.

[BulletOwner1]

Thunderchicken,

Do you have a trailer hitch installation business close? If you do I would humbly suggest you go and have them set it up. They know the height, angle, etc. They would probably charge a nominal fee but you could chalk that up to education for the next time and trust that it was set up properly. Safety is the biggest issue here, being able to control all that weight going down the highway at speed is much different than with the vehicle alone.

Don't mistake the local RV dealer for a hitch installation pro ! Not the same!!!

I just reread your post and have a question. Is the 6000 pound trailer loaded or unloaded? You may be at or above the limits of your truck, tongue and gross combined weight rating. Important things to consider, especially with safety and insurance coverage.....

Richard

[{tpc}]

Originally Posted by BulletOwner1

Don't mistake the local RV dealer for a hitch installation pro ! Not the same!!!

This is sound advice...speaking of, anyone have one in the southeast michigan area?

[Thunderchicken]

Originally Posted by Bob Landry

If the WD levels the truck in the process, that's just a side bonus, but it's unlikely that is going to happen unless the bars are adjusted too tightly.

The reason for adjusting the hitch and THEN doing the air bags is that when you raise the rear of the truck, that is essentially tilting the ball towards the front which reduces the amount of tension on the bars.

OK this is starting to sink in. Thanks. I think I'm going to spend a good bit of time at a local scale before I'm comfortable with whatever rig I end up with.

[Thunderchicken]

Originally Posted by BulletOwner1

Is the 6000 pound trailer loaded or unloaded? You may be at or above the limits of your truck, tongue and gross combined weight rating.
Richard

"Is the 6000 pound trailer loaded or unloaded?"
The 6,000# is the GVWR of the trailer. I expect the trailer to actually weigh about 5,000#.

"You may be at or above the limits of your truck, tongue and gross combined weight rating."
I intend be well under any limits. Off the top of my head, the hitch is 500# WC and 1,100"WD. (I didn't take the hitch limit into consideration for my first post. Being at the WC hitch limit, I'll be opting for a WDH.) The tow limit is 9,300#. And the GCVWR is 14,000# (Maybe 15,000#)

Thanks for your reply.

[Brent1974]

http://www.curtmfg.com/Category/40/Specialized%20Towing


This is a good video on installing a hitch, you might find it useful. But good advice to take it to a hitch shop the first time. See how it's done right the first time and have any questions answered that you might have.