Ford F800 suspension

[Walt]

Howdy guys,

I have a 1995 Ford F800 class 7 truck conversion, and it rides very rough. It has rear air suspension, but I'm pretty sure the shocks are worn out. So, I'm looking to get new shocks; would there be a different grade of shocks I could use that might make it ride smoother? If so, where might I find them? I never have much of a load in it, so it seems like the suspension doesn't need to be nearly as stiff as it is. Is there anything else I can do to improve the ride on this thing?

Thanks,
Walter

[Marc]

Hi Walt, And Welcome to the Best Truck Conversion Site on the web.(IMO) I am sure there are plenty of people here that can help you with just about anything you would need or know. You might want to leave some more information and specification's on your Truck in regards to the suspension system. A few examples such as. Is it a aftermarket?? Manufacture?? How Many Air Bags?? Weight of Unit?? (loaded) Do you also tow with it?? Is it Self Leveling or can you adjust it?? What it does and does not do. Really just about as much information the better. Again Welcome to the Forum.

Regards,
Marc

[Walt]

Hi Mark,

Thanks for the advice, and I'm glad to be here. I don't really know too much about the suspension system, actually; I bought the truck used and it came with no information whatsoever. I can tell you a few things, though. There are two air bags (one for each wheel in the rear), and there is a single height adjustment bar located between them. I do not know the weight of the unit; it's a Ford F800 chassis with a 24' box, with an overall vehicle length of about 32'. As far as the load goes, I'm sure it's much, much less than the truck was designed to carry -- I've converted it into a motorhome, so the only weight would be that of the conversion, people, bags, etc. The only thing I tow is my minivan, which I tow with a tow bar four-wheels down, so there is essentially no weight from the van on the suspension.

As far as performance goes, the problem is that the ride is very rough. The front suspension consists of leaf springs and shocks, and I'd say it rides better than the air ride in the back (but still not smooth by any means). It feels to me as though the rear suspension is set up to carry a very heavy load, which it just does not have at present.

Hopefully this information is at least somewhat helpful, and someone can steer me in the right direction.

Thanks,
Walter

[Marc]

Hi Walt, Let's start with a few questions about the airide.

So there are no Mfgs. names on any of the suspension components??

That would lead me to belive that it is not a factory installed system, Most likely aftermarket.

Is there any controls or a dump valve in the cab of the truck??

After the truck sits without the motor running for a few days do the airbags loose pressure??

Have you push or pulled by hand on the valve linkage that is located on the rear??

How long have you had the truck?? & Did it ever have a smooth ride??

What is the height differance between deflated and inflated airbags??

This is a start.

Regards,
Marc

[Warpath]

Do you have a metal cage frame for the box? That would add a decent amount of weight.

Air ride rear is going to be rated at 20,000 max, unless it was used in some sort of special application.

You really need to swing by a cat scale and get that thing weighted.

Also get the vin # and call ford truck dealer and they will be able to get you the spec's on the chassis. You definetly want to know what your front & rear axle ratings are. It is going to make is much easier to get the ride figured out with this information.

Things like tire pressure can be adjusted which can be huge in the ride department. Alot of tire shops will put 120 psi in your tires, when spec's show 95 psi is all that is required and I can tell you the ride will be night and day. But with out a weight ticket I wouldn't mess with anything. When you get weighted be sure to pull through twice and drop one side off the scale (if you can) to get a side to side weight.

With air-ride rear you really should be riding better than the front end, specially with weight on it.

[Walt]

Hey guys,

Thanks for the help. I'm actually away from the truck right now (for once!), so I don't have access to a lot of the information you're requesting. I do know that there are no controls and no dump valve in the cab, and the air bags lose only a negligible amount of pressure after a few days of sitting. I've only had the truck about six months, and no, it never rode smooth. I'm not exactly sure what you mean by pushing or pulling on the rear valve linkage -- what would I be looking for? It does indeed have a metal frame for the box, which I suppose must weight a good bit. The FGAWR is 10,000 LBS and the RGAWR is 23,000 LBS. Once I get back to the truck, I'll see what other info I can dig up, and I'll get it weighed and get back to you guys.

Thanks again,
Walter