Yelo

I've been looking at doing this for awhile....After ALOT of research and quite a few phone calls to some of the best known suspension shops in the industry here's what I've come up with: (Please feel free to tear this apart because I'm looking for any issues or "unfixable" problems)

Parts required:

* Upper bag mounts (they weld to the frame)
* 'Bags (Duh)
* 6" tall lower 2wd bag mounts (also called "cups"...these sit in the coil spring pocket in the lower control arm of a 2wd truck)
* Plumbing

Procedure: (Disclaimer: I'm going to assume that if you're considering doing this you ALREADY KNOW how to 'bag a 2wd truck....I'm just going to cover the differences)

* Create a lower bag mount "mount"....as the 4wd lower control arms do not have a provision for a coil-spring mount we need to create one, my reccomendation is to fab a plate out of 1/4" steel that uses the control-arm shock mount as an index/mount point, with good fab skills you could create a plate that drops over the lower control arm and another that comes up from underneath, bolt the two together to sandwich the control arm between the two. Another (and IMHO, better) idea would be to use DJM's dropped control arms, they're made out of steel instead of cast iron like out stock arms so you could weld a lower mount plate right to the arm (this is the way I'm going to go when I do this)

* The lower bag mounts are going to be the only really "wierd" part here.....find a set of 6" tall lower bag mounts (look hard enough and you'll find 'em), on each side of the mount you're going to cut out a 4" long, 1.75" wide U-shaped piece out....this is what is going to allow the front drive arms to remain in place. The bag/mount will now be "bridged" over the drive arm and sandwiched between the lower bag mount plate and the upper bag mount....exactly the same as a 2wd setup except you'll still have 4wd !!

* The upper bag mount will be ALOT higher on the frame than is normal on a 'bagged truck, this is because of the 6" lower bag cup.....that plus a 5" tall deflated bag and you've got a much-taller-than-normal bag setup, in order to allow enough room for bag inflation you've got to position the upper mount as high as possible on the frame....possibly higher than the top of the frame itself on a 1/2 ton truck so be sure to gusset the HELL out of this mount...a 4wd is HEAVY and ALL of the weight of the front end is on this mount.

* In order to lay the frame on the ground on a 4wd the front frame section has to be notched to clear the drive arm where it comes under the frame.....a U-shaped notch about 1.5" tall x 1.5" wide is all that is needed for the arm to clear the frame. Definitely be sure to box in the notch to help retain frame strength, compromise that and you're asking for trouble.

* The rear is that same as a 2wd....get as creative as you'd like.

Ideas ??

TurboBerserker

iTrader: (1)

Why not buy a 2wd lower control arm?

Nick™

iTrader: (2)

b/c that would place the bag where the coil spring would go on a 2wd, which is directly in the way of the front CV shafts, if I understand correctly he is shifting it over some so it won't interfere.... that's the reason why the IFS 4wd trucks have torsion bar suspensions, the spring would be in the way otherwise

TurboBerserker

iTrader: (1)

Yeah that makes sense -- I was visuallizing the bag perch in the middle of the lower arm instead of the shock mount lol.

shawn calvin

iTrader: (3)

i have a 91 4 wd that is bagged.it sounds like you have the front figured out. the back is a little different. i used kp components and the brakets dont line up with the holes on the frame.so i just welded them in ,other than that it is no big deal. if you have any other questions let me know. thanks shawn

Yelo

Actually the lower bag mount IS in the same location as the drive arm.....but the lower bag mount is bridged OVER the drive arm to provide clearance for the arm to still exist.

Yelo

If you've got pictures please post 'em up....as of right now this is concept only for me so I'd LOVE to see the end result from someone that has actually done this !!

Yelo

I had though about doing this as as it would have given me a pre-fabbed lower arm to work with, but the 2wd HD arms (which is what I need) also use torsion bars and the 2wd non-HD arms have a narrower track width and won't work with the HD front components

shawn calvin

iTrader: (3)

i can get some pics next weekend, i am in the works of installing a 4 link in the rear.i hope that i am all done by then. i just have to mount the tanks and compressors,plumb and wire. try to send an email to remind me.

thanks shawn

02BlueStepside

iTrader: (1)

Your way sounds very well thought out. All the ways I have seen usually include putting the bag so it pushes on the upper control arm, not the lower like it should be. One thing I have always heard is that you have to watch your cv angles though. You cannot drive with it low otherwise the cvs will bind.