rear air bags

[bmfpeterson]

I posted this post in the general forum and thought I should put it in with the other suspension gurus... so if I broke some rules sorry..let me know how to change it....

I am getting ready to do bags in place of the rear coils... but have a few delimas... I built trailing arms out of 2 x3 and instead of a bushings I did heims in the front. I am running a big tire and need to keep the bags inside the outside of the frame rail...if that makes sense...

So I was thinking of welding a plate on the arm to bring the bag inside enough to clear the frame rail, and a plate on the frame rail above to match... but is that going to mess with the handling and is the arm going to want to roll over because of the bag not being mounted on top of the arm?????

[N2TRUX]

Anyone?

[SCOTI]

The truck arms bolt firmly to the rear housing so it shouldn't turn (rotate) because of the heims. But the length of the arms w/the bags placed off-center might require some specific bracing to keep things as square as possible.

The farther out the bags & shocks are placed, the better for handling. So if you move them toward the center of the frame to allow the custom bag mounting positions, there will be some negative effects. How much is too much? What might bother one guy, another might not notice. That will have to be trial & error on your part to see how it feels.

[XXL]

Originally Posted by bmfpeterson

I am getting ready to do bags in place of the rear coils... but have a few delimas... I built trailing arms out of 2 x3 and instead of a bushings I did heims in the front. I am running a big tire and need to keep the bags inside the outside of the frame rail...if that makes sense...

So I was thinking of welding a plate on the arm to bring the bag inside enough to clear the frame rail, and a plate on the frame rail above to match... but is that going to mess with the handling and is the arm going to want to roll over because of the bag not being mounted on top of the arm?????

I would not recommend offsetting the bag centerline from the trailing arm centerline. While your built trailing arms may be stronger than the factory "pinched I-beam" units, offset bags are going to spend a LOT of energy trying to twist your arms.

Bags in the stock spring location tend to handle pretty well if you run separate valves for each.

[Frizzle Fry]

If tire clearance is an issue I'd build an offset upper mount further forward coming off the upper/inside of the framerail (as high as possible). Since the trailing arms are converging you can run the bags centered on them.

[bmfpeterson]

Frizzle fry,

I'm going to look at moving the bags up to the front of the truck and see how it looks...I've seen a few trucks with the bags mounted on the back side of the rear end, but I would think it wouldn't handle as good, and maybe have a little more body roll compared to the mounting them as far wide as possible....???

Has anyone mounted them on the rear end like that and had good results???

I just got my truck blasted and all of the metal work was finished yesterday. I talked to a painter and I'm pretty sure its going to paint next week???? so I'm on a mission to get this done..

thanks for the help

[bmfpeterson]

I am buying a set of firestone 2600 lb bags for the rear and am supposed to pick them up in the next couple days from another member on this site. are all bags that are rated for 2600 the same basic size as far as width goes, I have never messed with bags before so I am just wondering if there is a skinnier bag that I can use to make up for a little room.
also is this a god bag?

[Shane]

For what it's worth, the 2600 lb. bags are quite a bit larger in diameter versus the 2500 lb. bags. Most folks run the 2600 in front and the 2500 in rear. The below pics were swiped from www.***************** website.

2600 lb.
[img]http://www.*****************/files/Firestone_224c_2600.jpg[/img]

2500 lb.
[img]http://www.*****************/files/Firestone_255c_2500.jpg[/img]

[bmfpeterson]

I haven't bought bags for the front so I could just use these on the front and buy some 2500 lb for the back...what gives a better ride?

[SCOTI]

Originally Posted by bmfpeterson

I haven't bought bags for the front so I could just use these on the front and buy some 2500 lb for the back...what gives a better ride?

The large & small will work, but the smaller '2500's' are recommended for the rear.

[N2TRUX]

Originally Posted by bmfpeterson

....
Has anyone mounted them on the rear end like that and had good results???

If your going to mount them on the rear, I would run tapered sleeve bags. I am no expert, but that's what all the pro's recommend.

[bmfpeterson]

SCOTTI: Are the 2500's ever ran in the front?

N2Trux: why is that? I am pretty set on just mounting the bag in the coil spot and just getting the tire size to match, but just curious what the difference is??

I just got my trailing arms welded up all I need is now is to buy some solid stock to make a bung for the front side of the arm and I can get my suspension rolling....

[SCOTI]

Originally Posted by bmfpeterson

SCOTTI: Are the 2500's ever ran in the front?

N2Trux: why is that? I am pretty set on just mounting the bag in the coil spot and just getting the tire size to match, but just curious what the difference is??

I just got my trailing arms welded up all I need is now is to buy some solid stock to make a bung for the front side of the arm and I can get my suspension rolling....

Yes, they are sometimes used in the front but the larger 7"/2600's are the standard recommendation.

[bmfpeterson]

Thanks for all of the input... I need all the help I can get!!