Who has an Air Lift/Firestone rear air bag setup? I installed an Air Lift Load Lifter 5000 kit with the optional remote controlled compressor on my '08 E350 15 pass. cargo/tool van. Very convenient being able to press a button from the driver's seat after I hook my trailer and air up the rear. For increasing load capacity and eliminating the rear sag it works great. That being said, after using it for several months I am not going to keep it installed on the van. Here's why-the design of these systems limits the suspension travel to about 3 1/2", so without a heavy load or a trailer attached I was having a problem with the bags bottoming out without at least 20 psi. And it was harsh! It would make me cringe every time, feeling that crunch of the air bag mounts hitting each other. I could eliminate the problem by airing up to 28 to 30 psi but the ride became so bouncy it felt like I was driving a monster truck, to the point where my back started bothering me. I just ordered a Timbrens setup, it uses fixed pressure bags that look like the Air Lift type but the real advantage is that they only mount to the frame, with a separate "landing pad" that bolts to the axle. They will not cause a harsh or bouncy ride while driving empty since they are not engaged, and float until a heavy load is applied. I'll post back with my thoughts after I have a chance to road test them.
After all that, anyone interested in my old Air Lift set? It's listed in Ford truck parts for sale.

 

Thanks for posting your experience with the 5000 lb bags. I was thinking it would ride harsh and thats why I didn't buy any.
I thought perhaps the firestone 3000lb bags might ride softer, but movement would still be limited I think. Please let us know how the Timbrens system works for you, I would like to level the back of my van towing.
Andrew.

 

I'm waiting on your experience as well. I don't pull a trailer often anymore but I load my e350 pretty heavily including a rear hitch rack with 4 bikes, cooler, and plastic bins. I estimate probably 500 of hitch/tongue weight with the rack. My van doesn't ride too badly but sits down in the rear too badly for me. I like the leveled look, proper headlight alignment, etc.

 

Strike 2! I got the Timbrens kit and installed it the other day. Instructions say for light trucks and vans there should be an inch of space between the rubber and the plate and for heavy duty vehicles it will make contact and be preloaded, which my van was. I had planned to trim the rubber bumpers down enough so that there would be space during my normal unloaded height, then when I dropped material on the roof or hooked the trailer it would sag just slightly before the bumpers engaged. I was driving this morning and hit a bump and it bottomed out so I pulled over to look underneath. BOTH BUMPERS ARE GONE! VANISHED! DISAPPEARED! I actually chuckled to myself in disbelief and had to look twice to make sure I wasn't seeing things. The axle plate and the frame mount are still there along with the bolt and fender washers that hold the bumper but that's it. My guess is that the bumpers "squirted" out off to the side when I hit a hard bump. I'm going to take a pic and post it, and contact timbrens to see what they say. Ill post back with their response.

 

bummer, bad luck there. I'll be waiting to hear more about the fix.
thanks for the info so far.

 

So I just got off the phone with Timbrens, apparently the kit I got(FER35092B) is for regular vans and I should have gotten the RV/panel van set(FER35092LB), which has a harder rubber compound and won't deform as much under heavy loads. They are shipping a new set out free of charge tomorrow! Once I have a chance to use those I'll post back with my thoughts.

 

Cool. Scary pic though! I'm glad you can laugh, what else can you do?

 

You know, I've been contplating Timbrens or Air Bags for a long time now. For me, I only need a solution when pulling my travel trailer. With about 750# tongue weight, it seem like I need to raise the whole thing about 1.5" right at the hitch ball. Then everything would be level.

I sure don't need any extra suspension otherwise, but what if I took out 1 leaf and added bags? I wonder if the Timbrens ever come in contact while empty, that could be harsh. Also, would they act like a sway bar, tightening up the back end if you went into a corner a little hot? That 6500# trailer would push the van into a corner pretty good.

Nice thing about Timbrens is that they come with a full satisfaction guarantee.

 

Hmm, to be honest, for trailers, I personally use a weight distributing hitch. My farm E-Super has airbags, but that's really because it carries most of its load internally. If your trailer clocks in under 12,000lbs, you might want to look into a weight distributing hitch. If its over 12k, then why are you pulling it with an E-series You will find that your van's towing capacity is 'when properly equipped.' You will also find that that 'when properly equipped' means a weight distributing hitch.

 

95....: I'm using a WD hitch and have spent considerable time setting it up. I have the numbers written down if anyone is interested AND I posted them on an RV forum. That's a tough crowd! Self appointed weight and safety officers- all of them. Reminds me of a guy on here actually LOL. But I digress, the combo is just a hair over GCVWR for the V8 and way under for the V10, alas I have the V8.

Here is why I want help: the rear of the trailer is 1.5" higher than the front and the rear of the van "looks" like it is sagging. I suppose I could move the hitch up on the bar thingy that comes out the receiver. That might work, but I want to spend money on my van.

 

Well, when you add capacity with air bags, your ride will get more harsh. Even at their minimum PSI, they tend to give you ~300lbs of spring force, which is always affecting your van. They can never be at 0 PSI. The other possibility are overload springs, but the same issues rears its ugly head. the third option is to just rebuild your springs packs to be a bit stiffer. I did that with my ARES van, but that only makes sense if the van is loaded full time. A fourth option is the Timbren rubber spring system. Though, a member on the forum right now is going through issues with their system. In its defense, Tembren seems to be on the ball.

 

You cannot add any capacity with helper springs nor air bags. You can however use them to better support the rear and keep the van / truck level and eliminate the handling issues that come from a squatting rear end.

I have air bags my truck, but it had a 6250 lb rear axle capacity before I added them, and it still has a 6250 lb rear axle capacity after I installed them.

It does ride more level though at maximum axle capacity, but I still cannot legaly or safely haul any more weight without overloading the rear axle.

I have thought about adding them to my E150, just to better level it out when loaded, but I too have found that the air bags do roughen up the ride due to suspension travel reduction, even when at low psi. I value the soft ride of the E150 so I may leave it as is.

David

 

Now this I don't understand. I drive an all air ride tractor trailer for my work and as long as I load it right, the ride remains supple. Meaning that it is a flat deck and if the load is concentrated in the center instead of the ends or if I've taken the arch out of it by improper dunage placement, it will ride like an empty E350! Empty it is always rides nice.

Now I'm hearing that air bags worsen the ride if there's no load.

 

It is mainly because your rig was designed as a all air ride in the first place, with the proper suspension travel built in. You also do not have the different spring rates of a steel spring and a air bag fighting each other. The air bags in your case is not constrained nor limited by the steel spring designed suspension.

So the aftermarket add on air bags are generic in that they fit many applications, so they are not optimized for a paticular truck / location of the bag relative to frame and spring / air bag capacity matched to the exact steel spring rate / suspension travel as designed into the existing suspension system / etc. And as well they are not the primary weight handling portion of the suspension, but mearly a assist.

And since that assist cannot be fully removed from the suspension when not needed (you need a minimum air pressure), it has the effect of firming up the overall unloaded suspension over what the factory spring only was.

If, the rear end was redesigned to be fully air suspended, like your rig has, then yes, the unloaded ride would be much improved.

Funny thing, a class 8 truck can ride better than a one ton truck!

David

 

Heh, I meant to type Spring Capacity. GAWR and GVWR are a function of a whole lot of other things besides sitting level.