The last couple of months issues of OFF ROAD magazine have pretty good articles on linked suspension design. If you are considering a link suspension it would be well worth the cost to pick up these issues. They do a pretty good job of laying the different types of link designs out there.

Sorry for the # of posts, but I keep thinking of things.

The #1 problem the we all encountered with SAS is the front drive shaft. They are very short on the isuzu. Every one who has built with a low pinion axle has had a devil of a time getting it to work properly. Until I designed and built my dual t-case set up I was spitting shafts every time I went out. The dual case completely solved my DS problems, but I have wheel base to work with on the trooper. A linked front end will help with DS issues and will reduce the plunge on the DS. Rear mounted shackles on leaf springs would be the worst as far as plunge goes.

Using a HP axle solves half of the problem right from the start. I know that it increases the up front cost, but in the end you may save $ because you won't have to build aroung the problems a LP axle creates.

One possible solution is to do what I did on my axle. I started with a chevy d44. I then cut off the knuckles. Measured and shortned the tubes. I then gound down the knuckle welds and pressed out the cut off tube section. Then I put the knuckles back on and rotated the pinion up about 20*. I chose to match the width of my rear axle at 59". The downside is that I have a custom long side inner shaft. I use a waggy short side inner shaft. In retro spect I would have gone with the waggy width on both sides. this mod essentially raises the pinion up to around HP axle height, and releaves u-joint angle at the axle end. Your only extra cost would be to pick up a chevy d44 housing to modify,I bet you could find a free housing if you looked around.

Thanks for all the replies. I'm not sure if I'm going to have drive shaft problems or not with a 4L60E automatic trans and Dana 300 T-case. I am, however, worried about clearance to the trans pan, it's extremely tight. I pulled the shaft from an old Full Sized Jeep (Same donor as the D44) and it seems to be just about the right length. The drive shaft uses a double cardion but from the angles I'm getting I don't think the U-joints will be a problem. I won't be able to use a double cardion up front but may VERY well need one in back since I'm currently planning on angling the drivetrain with the engine lower than the T-case so the T-case will tuck up as far as possible.

Chad... You were certainly right at least with our rig there is NO room under there for a triangulated 4 link. With as close as the steering linkage is looking, I don't think I'm going to manage a pan hard bar either. Or if I did, it would be pretzilized (I made up a word!) and I'd have to fight/design everything kind of on the fly since the clearances would be so tight.

So it looks like I'm going to go with leaf springs, SOA style. Embedding the leaves in the frame. The fun part is the springs ends/bushings are about 3" and the frame is about 2.7 OD. I haven't started hacking up the frame yet but suspect tomorrow or the next day I'll start. Doing it this way should lower the front about 2" and it's still going to be pretty tall.

I've known I wanted to add a winch, so the extra length to mount the springs isn't a big deal, and I'll embed the shackles in the front up inside the frame extension as well.