As you may have noticed, I HAD a an IFS Chevy truck. The IFS system had several problems that a good solid axle swap solved. It also allowed me put a locker in the front diff, and to run manual hubs. The electric axle disconnect was always a pain. I would not suggest this to anyone who doesn't really off-road their truck. I will also say that the Procomp lift kit is a great product. I never broke a single component in over a year and a half. I did, on the other hand, break numerous Chevy front suspension parts. The stock suspension parts are just not designed for 35's.
The swap is a reasonable undergoing if you have good fabrication skills, and the tools to match. It is also quite cheap, compared to an IFS lift kit. There are thousands of ways to do this lift, so mine is just an option to look at. I chose to start off with a leaf spring suspension. I am looking into a coil-over shock setup, but that will be later on down the off-road. I designed a system that is completely bolt-on. During installation, it is necessary to cut off some of the factory brackets that will be in your way. Other than that, all you will need to do is drill a few holes, and bolt on a few brackets.
This is a picture of the front crossmember. The part is made out of 1/2" A36 steel plate, 2 1/2" .25" wall square tubing, and 2" .25 wall square tubing. I believe in one simple rule, OVERKILL! I also decided to integrate a 2" receiver hitch into the bracket. A front receiver hitch is quite useful; make for a great tow point and winch mount.
Installation of the bracket is quite simple. It just slides up on the frame from the bottom, and is held on with 5 grade 8 bolts per side. Two bolts go through the tow hook holes, and three bolts into the bumper mounting holes. Due to the wrap around design, there is very little stress on the bolts themselves. The leaf springs are held in by 9/16" grade 8 bolts through the lower holes in the bracket.
This is a picture of the shackle brackets. They are of my own design, and are a little unorthodox. The upper mounts on the shackles are 3/4" heim joints. I did this in my quest for crazy flex. You will see my shackles a little later. The brackets are made of 1/2" A36 plate and 1 1/2" solid bar stock. The brackets are composed of two plates. The shackle is mounted to the bracket via a 3/4" grade 8 bolt.
The brackets sandwich the frame just inside the boxed in section behind the body mount, and are bolted together with 5 grade 8 1/2" bolts. See the little image above. Five holes had to be drilled in each frame rail. This was the only drilling required for the entire installation, and one of the holes in each frame already existed, they just had to be opened up slightly. That made it very easy to mount each plate in the exact same spot on each frame rail.
I designed a nontraditional shackle for the swap. It is a two piece design, as you can see in the picture. The shackle stays in its compressed state when the vehicles weight is on the tires. The length (eye to eye) of the shackle in this state is 6". When the weight of the vehicle is removed from one of the tires (when the axle droops) the shackle will start to unfold until it reaches its full length of 12". This provides an extra 3" of droop. The shackles also have rod ends at each joint. These rod ends provide up to 12 deg. of side-to-side motion at each joint allowing the springs to lean without twisting.
I replaced the hydraulics with a standard crossover system. I bought a flat top knuckle and steering arm from offroad designs and the matched up a couple of tie rods from the local parts house. The system is much better on the road than the hydraulic one that I was using. You get great feed back and minimal slop.
I NO LONGER USE HYDRAULICS. IT IS NOT SAFE FOR ROAD USE!!!!!
I have sense changed over to a standard crossover steering setup. I purchased a flat top passenger side knuckle for my Dana 44. I machined a drag link from 1.5" solid bar and use a couple of 1-ton ball joints that I searched long and hard for at the local auto parts store. The new setup is much much better for road use, with only minimal draw back offroad. The hydraulics are fine for offroad only applications, but I would suggest not using this system on the road.
OFFROAD ONLY STEERING
I used to run a hydraulic steering system. It proved to be an easier system to fabricate and install than a standard drag link setup. The primary benefit of using this setup, is the complete lack of bump-steer while still maintaining "road-feel". It is a manual system, therefore it does not use a pump, so there is almost nothing to maintain. As the image on the left shows, the system consists of two hydraulic cylinders, a couple of needle valves, and a tank. The valves and tank make up the bleed system for the cylinders. Air in the lines causes lots of steering play.
The rod end of the upper cylinder is mounted to the pitman, arm and the other end is hard mounted to a custom bracket that bolts to frame. The bracket is made of 1/2" and 1" plate, and is held on by three bolts in the side of the frame and by a single bolt through the lower control arm mount. The three frame bolts had to be drilled. The steering box and pitman arm are left unchanged.
The lower cylinder is attached to an adjustable bracket
that bolts to the axle housing. This bracket is used for centering the steering
wheel and tires. The rod-end of this cylinder is
bolted to a bracket that is welded to the tie rod. The lower cyl. is basically
installed like a stabilizer.
First, the valves are opened and the whole system is filled with hydraulic fluid. The air is then forced out of the system by first moving the tires lock-to-lock by hand, (hint: raise the vehicle's front tires off the ground first, it makes it a lot easier) and then by turning the steering wheel lock-to-lock. The steering wheel and tires are then centered up and the valves are shut.
Now, when the upper cylinder is stroked and compressed by the pitman arm, the lower cylinder will move in the opposite direction forcing the tire to move.
The original idea for this system was given to me by Steve. A bit later, the bleeding system was proposed to me by Roger, who wanted me to be his testing dummy, before trying it on his own rig. Thanks ya'll.
FRONT DRIVE SHAFT
By far the most difficult piece of equipment to fabricate was the front drive shaft. The large amount of lift and the crazy amount of flex made using a standard drive shaft impossible. The angle between the transfer case flange and the front pinion is about 20 deg. when sitting on level ground. After numerous attempts were made by local shops to build me one, I decided that I would have to design my own. I took my plans to DRIVE LINE SERVICES CO. in Pasadena, and they made it a reality. It is one crazy shaft. I had to make it a two piece. The lower shaft is pretty common except that it has open u-joints at each end. The upper shaft is the crazy one. It is only 7" long, and it is made up of a single u-joint and a support bearing. The bearing mounts to a custom bracket made by my buddy Kent. It sits up on my transfer case crossmember and has a slightly downward angle to it. Here is a pic of it:
To Main Page
Well, that is my ride. If you have any questions or suggestions please e-mail me at firstname.lastname@example.org