Airbags and leaf springs?
 

I've seen quite a few vehicles where they took out all but one leaf in the springs and then put in airbags. My question is how much adjustability will this give me, and where could I put the bags? The truck is a 72 longbox C10 with the factory rear leaf setup. Also, how low can I go with just bags replacing the coils up front? Basically, I want to bag my leaf truck and keep a big range of adjustability. Thanks!

There are a few drawbacks to "mono leafing" your truck(or any truck for that matter)...

You will most likely get some wheel hop.
You will most likely get some spring wrap.
You will most definitely have issues with your pinion angle
You will be limiting your ability to drop super low(if that matters to you.)
Your ride quality will not be that nice.

I would recommend saving your money and 4 linking the truck. You will be much happier in the long run.

Now, to answer your question. Most people will mount the bags directly over the axle tube. You can figure on getting approx 6-8" of drop/lift with this setup. With my 91' GMC, I am getting 13-14" of lift using a cantilevered, triangulated 4 link(bags are mounted on the link bars). The front is easy. Just swap the coil for the bag. Suicide doors is selling the front brackets for like $59.95.

I wouldn't recommend going so far as to take all the leafs out but one. If you leave two it will ride much better. I know the frame of a 67-72 is different from my 77, but you take a look at mine and get an idea of how to do it.

In the front your limit will be determined by the height of the tire. Your tire will hit the fender liner before your truck hits the ground. If you cut your inner fender out, the next obstacle will be you crossmember hitting the ground.


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Thanks for the help guys. I would like to do a 4 link, but with all the other work I'm doing the funds just aren't there. I like N2trux idea, with a couple leafs left in the pack. That makes sense to me and I may just try that. Thanks!

n2trux, seeing that you have the monoleaf rear bag set up can you confirm that any of these are true, as suggested by bagged 91:

You will most likely get some wheel hop.
You will most likely get some spring wrap.
You will most definitely have issues with your pinion angle
You will be limiting your ability to drop super low(if that matters to you.)
Your ride quality will not be that nice.

anything you would change or advise otherwise now that youve got yours set up? thanks , john

When I first did hydros on my Mazda 12 or 15 years ago, I went monoleaf. One thing you really need to be concerned with is that the spring isn't too long to go real low, and binds because the shackle doesn't have enough travel. If it does, the spring will bend in the wrong spot and eventually break. It's usually right in front of the axle. Why do I know this? It's the reason the truck ended up with a 4 link.

Most guys that initially go with an AOL (air over leaf) setup end up replacing their setup and going with a 4-link. IMO, spend the extra money up front and do it right the first time. You're only going to thank yourself in the long run. Monoleafs, like Z16 stated are prone to breaking. This is a proven statement. Not only are they dangerous, but your truck will ride like a dumptruck. Now, imagine your truck cruising down the highway at 60-70mph and hitting a big bump and then snapping one of your leafs. Not a pretty sight. It happens.

I am going this route with my '87 LWB soon, cept i am not gonna go too low. I have a flip kit installed already and have about 2 inchs from the axle to the aftermarket bumpstops. I don't think i'm even gonna install the c-notch. I think i'll just remove one or two leafs so i can lay it out more when parked. That would give me approx 8" s of drop. I know LOTS of local guys who have lowered their rides via AOL, exactly like N2TRUX, and never had any problems. Like N2TRUX stated you would want to keep at least 2 leafs, which provides latteral stabillity. I ran with a static 11 - 12" drop in the rear of my '87 SWB for a few years and it drove fine, well, actually better than stock. I had no bags at that time mind you, but if anything that would create less wheel hop. The pinion angle gets pretty extreme going that low with leafs, but i never did have any problems.

11-12" static drop?????? Umm, I don't think that is even possible to have it that low static and still be driveable. You'd have to have a flip kit, shackles, hangers AND drop leafs. Flip kit=6", Hanges=2", Shackles=2", Drop leafs=2-4" depending. Also, if you do decide to do the AOL setup, at least notch the frame. It's kind of pointless to do all that work to install bags and then not be able to drive it low or even air it out when parked. The notch will give you an extra 2-1/2" or more of clearance. (which you'll want, trust me)

Let me clear a couple of things up. My truck is not a "monoleaf" seat up because it has two leafs. I would not use this set up if I planned to run a step notch. For a mild drop with a C-notch two leafs "will" work.
Now to answer your questions more directly-

You will most likely get some wheel hop. If you have a motor with some real power that might be an issue. I have not had any trouble, but my stock motor only had 150hp when it was new.

You will most likely get some spring wrap. You will get spring wrap with leaf springs no matter what. The set up I am running has never had a problem with "excessive" spring wrap.

You will most definitely have issues with your pinion angle False. All trucks are different but because of the driveline angle on 73-87 trucks pinion angle is usually not a problem. If it were a problem, it wouldn't matter how the truck is lowered.

Your ride quality will not be that nice. False. For the most part your truck is being supported by the air bags, not the springs. I have had many people ride in my truck and they are amazed at how well it rides. Then again I'm not running 30 series tires which will cause a rough ride.

In2trux- will that setup work on my 79 blazer- it looks like just what i'm lookin for..........

There is no reason why it shouldn't. I know the Blazer frame is different, but the same theory applies. I read in your other post you just wanted bags for overload. If that all you need a small set of helper bags will get the job done.... :cool:

Re: Airbags and leaf springs?
 

im hopping to get a c30 soon and am definitely going to try the air over leaf idea but a little differently. I will take out all but 1 leaf. mount the bags inside the frame in front of the axle. to prevent axle wrap. mount shocks inboard frame on the back side of the axle, mostly because limited space. if axle wrap is still an issue ill move to 2 leafs. if its still bad ill 4 link the truck with a pan hard. if the shackle doesn't clear i will come up with some custom solution. im guessing dropping the rear shackle mount down and putting on a drop shackle which results in the same ride height would fix this problem since the spring has to travel a much further arc length to contact anything. ill leave the front static with drop spindles and maybe 1/2 - 1 coil cut. for the time being. Mainly want bags for towing but also want to go low. i figure why do load level bags when actual bags are about the same price and my own labor is free..

Re: Airbags and leaf springs?
 

Just 4 link it no point an having just one leaf spring

Re: Airbags and leaf springs?
 

Air bag over mono leaf and towing sounds like a very bad idea to me.

Re: Airbags and leaf springs?
 

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