Airbags with a straight axle

[misfits1981]

Morning all - I tried doing a search but couldn't find a thread for my question(s). I have a 1957 3100 that's lowered with lowering springs front and rear but I still want to go lower. My dad and I found a guy at the Pomona Swap Meet that will bag the truck, front and rear, with the stock straight axle on the front.

My questions are - has anyone done this? If you have, what's your experience? I know IFS is the way to go but my dad is reluctant to cut the truck up since the sentimental value is higher than the cost of upgrading to IFS. Any pics or input is appreciated. Thanks!

[1-ton of fun]

I haven't seen it done, but I don't see why it won't work. He will need to make some control arms to mount the axle to the frame and define it's range of motion. Not a lot differnt than modern 4x4 hd trucks like f250's except with bags instead of could springs. Will also need something to control side to side motion like a panhard or watts link. Again, not hard to do.

[NEWFISHER]

My 50 had spent a short time of it's life with bags up front on the straight axle. The frame mounts are still there The old axle had a pan hard par mount welded to it and the previous owner was running a 2 leaf pack in the stock hanger and shackle mounts. I suppose it would work, but I yarded it all out and sent Sid the front axle as a core ( he tossed in in the trash because it had been welded on) I wouldn't want to run it at 75 mph. unless you fabbed a 3 link style system as 1-ton-of-fun mentioned

[OneOffStroker]

I haven't seen it done, but if you make some adapter plates that bolt to the axle where the spring perches are, then you should be able to get it done without welding on the actual axle. You will definitely need a trailing arm on each side and a pan hard bar. You can also have the bag mount to the adapter as well, so that it is one fully contained piece. The crappy part will be your steering linkage. I guess a lot of guys that go with really low mono-leafs or dropped axles have issues with massive bumpsteer due to the pitman arm length, or something like that...

[NEWFISHER]

Or do a power rack / straight axle conversion

[misfits1981]

The guy that does the work leaves the leaf springs in tact so there is no need for a panhard bar since it is essentially the stock setup still. He adds bag mounts to the frame and axle and de-arches the leaf springs. So the kit is a dropped axle (and correct steering components), de-arched springs, and bags. Just wondering if there is any other truck out there with a similar setup?

[mr48chev]

Even with two leaves left and good bushings I would think that you will get more lateral motion than you want to deal with if you really drive the truck more than just posing around town.

With what I see in my mind that you are saying you want to do I'd just drop the I beam idea and go independent and be done with it. There are lots of proven and safe ways to do that so you can build a truck that will go as low as you want or even to low while being capable of being driven at any speed it has power to drive at with relative safety as far as the handling and predictability of what it is going to do when. 70+ on the freeway with a cobbled together airbagged I beam setup might be creating a situation where the truck wants to change lanes with a road surface change without giving notice that it is going to do it.

[misfits1981]

After some thought and looking at the truck I think it's up to me to convince my dad to cut the truck. I searched for a Camaro clip on Craigslist and found one for $500. Is there a particular year range to look for with a Camaro clip?

[whitedog76]

Originally Posted by misfits1981

After some thought and looking at the truck I think it's up to me to convince my dad to cut the truck. I searched for a Camaro clip on Craigslist and found one for $500. Is there a particular year range to look for with a Camaro clip?

I think you're on the right track. I think you'd be opening a can of worms with trying to go to an air ride setup. Not only would you need to fabricate some sort of 4 link/Watts setup and trailing arm, you would need to move your steering box and modify your pitman arm and drag link setup. The location of the stock steering box would make it next to impossible to get a bag mounted between the axle and frame.

[1project2many]

The guy that does the work leaves the leaf springs intact so there is no need for a panhard bar since it is essentially the stock setup still. He adds bag mounts to the frame and axle and de-arches the leaf springs. So the kit is a dropped axle (and correct steering components), de-arched springs, and bags. Just wondering if there is any other truck out there with a similar setup?

Kit might work but that means bags are working against weight of truck and pressure of springs trying to return to rest position. Low buck answer and probably practical solution but don't forget axle roll during bumps and stops. And the problem will be worse with fewer stock leaves in place. Axle roll causes bags to twist or scrub each time truck stops, bumps, etc. Bag life could be compromised. Best approach is four link to keep axle alignment geometry with watts to prevent lateral motion. IMO this would far superior to many bagged IFS vehicles where alignment angles are a compromise and truck ends up running poor angles much of the time.

Then again, I've argued a solid axle front can be superior on a roundy-round track too, so what do I know?

[Chris.]

I would not do it usung leaf springs it's a half assed way to do it nowadays all the mini truck people who started using bags did it with leaf springs but that was mostly abandoned in th 90's

Here is a link to the only way I think it would be ok it's not the same truck but the axle setup is essentially the same

http://dropndrag.com/dnd/viewtopic.p...761&hilit=ford

[mr48chev]

A setup to the one that Chris showed the link to would work fine on the truck in question but but those photos clearly show the issue of the axle hitting what is above it if you want to lay frame with the truck.

The Camaro front suspension is a decent way to go on that truck but for 500$$ I'd want that subframe to be in ready to drive shape and not needing new bushings, ball joints or rotors. 500 seems to be at the upper end of the price scale for one out of a wrecking yard.

If you are good with the way the truck rides and steers now you could send your axle off to Sids to have it dropped and either add some lowering blocks or rework the rear suspension a bit to get a decent static drop that would have the truck right down in the weeds.

[whitedog76]

That setup seems to be well made and thought out, I'm still not a fan of it. Do you realize the stress put on those 4 bolts in that axle? Not to mention the added stress on the top flange of that straight axle. Not for me. I'll stick with U-bolts and leaves.

[dubie]

I dropped mine with mono leafs and a 3" dropped axle. It sits just right and the ride is pretty damn decent. Everyone asks what clip I have up front and then have a look of shock on their face when they take a look under it and see a beam

[58APACHEE]

i actually met a guy with a 56' i believe, he had bags on his axle i got pictures of it (cant seem to want to load) he said he never had problems with it, pretty interesting the way it was set up....... (if any of you guys want to see them i can e-mail them to you and maybe you can post them, i got to frustrated and gave up on trying to load them)

[1project2many]

I'd love to see 'em. Just because a design has technical drawbacks does not mean it's not a practical solution.

[58APACHEE]

1project2many.... send me your email...maybe you can post them!

[58APACHEE]

[IMG]C:\Users\jgarcia\Pictures[/IMG]

[1project2many]

PM Sent.

[OrrieG]

I have been following this discussion and am trying to figure out if I am missing something.

I thought the function of a 4 link was to allow the axle to move in a vertical arc, with both sides traveling together (think prostock where you want power equally distributed down to each side). The the linked photos the front 4 link is equal parallel arms with welded brackets at each end to the frame and axles. As each side moves independently vertically thru the arc won't that want to warp the axle if the other end is not moving at the same direction and rate? And over time will that cause fatigue at the welds? And you have the added forces from the turning movements.

I think it is will be a very stiff, unforgiving ride, with limited real travel that will eventually break at the weakest point. Having the frame connection fabbed similar to a leaf shackle arrangement might help.

[58APACHEE]

[58APACHEE]

1project2many..... thx figured out what i was doing wrong!

[1project2many]

Great! Thanks for posting them.

[1project2many]

Four link suspensions are built with varying degrees of travel. Technically your '64 Chevelle has a four link on the rear. GM placed the upper arms at an angle and connected them near the center of the axle through bushings to allow the axle a greater range of rotation.

The system in the pictures is not going to allow large range of axle rotation. This may be intentional. The builder may not expect much suspension travel and may believe axle twist is not too likely. There are Heim joints on one of the arms and will allow for some motion. I haven't followed his thread nor have I spent much time looking at the photos to see the final product. I would not expect a small amount of twisting to damage the forged axle. I would expect that roll resistance would affect ride much as a sway bar would. Driven mildly that system might be good for many years. In my hands it might not last so long.

[OrrieG]

1project, thanks for the insight, just thought it might be educational for me and helpful to the OP. Heim joints will definately help. Re the Chevelle, before poly joints the old school trick was to drive 16d finish nails into the rubber bushings to stiffen them up!