Being New Years Day, I thought it would be a good time for an update on my project. Some of these photos have been posted here and on the other forum as I've worked on the suspension over the last 13 months. (I took a 6 month summer break to do outside projects to keep family happy)
I have the suspension mostly complete now, and am about ready to move on to the cab and sleeper frameing. I will be moving from one area of the project to another as lack of finances require. LOL
A rough drawing of my project. 1947 Autocar U-70 cab set on a 1980 International frame with fabricated air suspension, Detroit 6v53T engine and Allison 2400 transmission. The engine will sit under the sleeper cab with a small dog house in the front of the cargo area. I plan to have a 5th wheel mounted in the cargo area to pull a large travel trailer.
Sorry, I don't have a closer picture from this view. This is the rear suspension in full compression, rear rear axle is chained up as high as it will go, front rear has all air out of bags. Notice the small air bag that is used to raise the front rear axle off the ground. All suspension links are parallel with the ground at ride height. I don't know if that is best, but it was simple to keep track of.
A better view of the small lift bag for the front rear axle
This is an overhead view of the rear rear suspension. The upper arm is triangulated to a bridge above the center chunk. I used a bridge because I didn't want to weld to the cast iron center chunk, the nickel rod required is expensive and cast iron welding it not my area of expertise. Upper and lower arms are made of 2"X3"X1/4" wall mild steel tubing. The upper bag mount is 5/16" plate steel, it is bolted to the frame. If you look carefully at the upper bag mount you can see a vertical relief cut and welded in the frame for bag clearance, there is also a "C notch" cut in the bottom of the frame so the frame can be lower.
An in process picture of the rear rear lower control arm frame mount. All mounts are bolted to the frame.
An overhead view of the trailing arm axle mount, on the front rear axle. Two bushings in tandem to resist rotation, but somewhat compliant to twisting forces.
An overhead view of the front rear axle trailing arm. (2"X3"X1/4 wall tubing)
The arch in the front rear axle for drive shaft clearance. (unfinished) 4"X4"x1/2" wall tube. I somehow need to attach a panhard bar to this axle, but it can't interfere with the drive shaft. Not sure how I will do it.
My bushings 2"X2"X1/4" wall tube 2 1/2" long, 1 1/2" square rubber with 7/8 through hole 2 1/2" long, 7/8"x5/8" round tube 3" long, not shown 1/4" rubber washer on each end. 13 required
Overhead shot of my steering set-up. I used the steering box that was on the fire truck. The steering box and drag link are at a 30 degree angle to the axle. Originally this axle was a normal cross steer set-up so I didn't have to change any of the original tie rod parts. the drag link will be stretched about 3"
These are the original suspension arms and axle attachment from the 1997 1 ton 4wd Dodge dually. I carefully measured the original truck so the arms are located the same as they were from the factory. The mount that attaches them to the frame got a little tricky and took a couple of tries, but I'm happy with the way they turned out. The panhard bar isn't shown in the picture, but it also mimics the original using the same axle mount. It isn't noticeable in this picture but this was a driven axle (4wd) that I removed the center chunk from and replaced with a heavy walled tube. I got a real good deal on the front and rear axles on Ebay and not needing or wanting a 4wd this seemed like the easiest way to proceed.
A close-up of the lower bag mount on the front axle. The original Dodge suspension used coil springs, I modified the spring holder with a flat plate to hold the air bag. Very simple conversion. Notice the splice in the axle tube just to the frame side of the spring mount, the rusty piece is slid over the original tube 4" and the joint has 8 1" plug welds joining the 2 tubes.
“He, who is without oil, shall throw the first rod” Compressions 8.7:1
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