I had a problem with clearance between my drive shaft and the drive shaft tunnel. To get the car low like I want, the drive shaft kept hitting. It was either remove the interior, build a bigger tunnel, then reinstall the interior, or come up with a smaller diameter drive shaft. The drive shaft is also quite long, about 60 inches. Studebaker originally had a 2 piece drive shaft in these cars, perhaps for some of the same reasons I have decided to revert to one. By going to a 2 piece shaft, I can reduce the diameter, which helps with the tunnel clearance on the sides, and also moves the pivot point back further which helps with clearance on top. The shorter shaft also reduces any drive shaft critical speed problems I might encounter. Here are pictures of the drive shaft built for me by Driveline Specialties in Paradise CA. From their experience building drive shafts for trucks and motorhomes adding Gear Vendor overdrives, they have learned that when you have a short front shaft, a CV joint must be used to avoid the front shaft vibrating. Since we wanted to mount the support/carrier bearing in the same place that Studebaker did, the front shaft had to be pretty short.
At this point in the project I do not have an onboard air control system, I have some pieces, but still need to acquire the rest. So, I just installed a short piece of air line with a Shraeder valve on the end for each air bag. That way I can raise and lower the car with shop air until I have the rest complete. In the pictures below you can see the car at the low height, then near the highest height. I took the car for a test drive to see if the stronger springs and new bushings made a difference in performace. I am very pleased so far. All the clunk noises are gone and I no longer feel the axle wrapping up. I still have a little vibration under certain conditions and may need to adjust the pinion angle. I did a burn-out in the drive way (picture 3). You can see evidence of one done previously that only spun the right tire because of the weak springs allowing the right side to lift, then you can see the most recent one where both tires spun evenly, though the right tire was a little low on air by the mark. The car seems to hook up much better also. I will declare this a success! Next step will be the onboard air system. Thanks for looking.
First step was to install the lower bracket on the spring. This required loosening the U-Bolts and lifting the axle housing so the bracket could be placed between the spring and housing. This did not leave much of the spring bolt sticking up to position the rear end on the spring. There was enough to get it in place though. I fastened the bottom of the air bag to the lower bracket before installing and offset it one hole to the outside for proper positioning. Once that was done, I place the upper bracket on top of the air bag and positioned it against the frame. Because of the shape of my frame I was only able to line up 3 of the 4 holes on the bracket and have it mounted anywhere close to square. I have confidence that 3 bolts should be sufficient to hold it, but if it proves otherwise we will weld it in place. Once I had the bracket positioned, I clamped it in place and the installed a tire to check clearance. The tire would not even go on, so I took the swazall to the bracket and trimmed off the unneeded portion and checked again. This time there was adequate clearance, so I cleaned up any rough corners and edges with the grinder and gave it a shot of black paint. Next I drilled holes one at a time and bolted them in place to maintain position. Studebaker has a boxed frame and I thought I was going to have to drill all the way through, but there is an access hole right where I neded it so I was able to reach inside the frame to install the nylock nuts and get a wrench on them to tighten them up. I then repeated the operation on the other side. In the pictures below, you can see the installed air bag with the axle lowered and no air, then the airbag with the axle raised and no air, and finally the airbag inflated supporting the weight of the car. I should have dusted the filings from the drilling off for the pictures, but I guess I was over anxious with excitement!
After much study, I decided that I have enough clearance to mount air bags on top of the springs instead of using an air shock/Shockwave type set up. I think this will give me a better ride and still have good shock absorbing performance. I purchased Air Ride Technologies "Air Over Leaf" package from RJay's Performance Center (http://www.rjays.com/Air_Ride_Tech/air-over-leaf-01.htm). I went with the ARK 2002 model desighed for 2.5" wide springs and side frame mounting for the upper bracket. This is designed to work like an overload spring with your existing leaf springs. With the de-arched and strengthened springs I will be able to adjust my ride height for extra weight in the car or tuning performance and lower the car when I want to for that great low look. The first picture shows where the air bag will be located ahead of the rear axle. The second picture shows the kit laid out on my work bench. Notice the upper brackets, I had to trim them for tire clearance. I did not think to take a picture of the trimmed pieces before installing them, but you can see how they are trimmed in later pictures.
For my fuel injection I have an intank pump and a '99+ Corvette Fuel Pressure regulator. I originally had it installed in front of the tank. This workded OK, but is very close to the rear end housing and the fuel lines had to be shielded from exhaust. (See pic 1) While I had the tank out to make working on the springs easier I decided to relocate the regulator behind the tank. I mounted it on the crossmember that holds the tank, it is protected there by the rearmost frame crossmember. I was also able to reroute the fuel line so it is not as close to the exhaust. (Pic 2)