MonsterGM
10-31-2003, 05:23 PM
This may be hard to visualize, but here it is:
I'm putting a SFA on a '96 GMC Jimmy. I plan to mount the shackles from the inside of the frame-rails. There is an existing hole in both sides of the frame that can be used to build off of. Basically, the hole is about 1/2" and a 1/2" OD piece of pipe will fit perfectly in the frame. Also, a 5/8" bolt will be a very close fit inside the 1/2" pipe, that when lubricated, would serve as a decent bushing. So, at this point, you are looking at a boxed frame, with a 1/2 pipe running through it, and welding in place with about .25" sticking out on both sides (for the weld bead). There is a 5/8" bolt passing through the pipe, flush with the outside, and sticking out about 5 or 6" on the inside. Now, it's time to hang the shackle. The shackle will be constructed from 2 flat-steel bars spaced apart just enough to sandwich the leaf-spring bushing. At one end of the shackle will be holes drilled for the spring bolts. At the other end will be 1/2" holes drilled to accept another 1/2" pipe, which will run through both steel bars, and welded from the inside. This will form basically an integral schackle/bushing assembly. Now, you are looking at the above image, but with the shackle and bushing slid onto the 5/8" bolt sticking out of the frame. The whole thing will be retained by 2 nuts tightened into each other. The idea here is to securely retain the bushing on the bolt, but allow just enough freeplay for it to rotate without grinding and binding on the other pipe in the frame.
Does this sound like a good way to build a bushing??? Does it matter that nothing is "rubber isolated" Can you buy pre-made shackles with bushings already pressed in??? When you tighten the bolt, what's to stop the whole thing from binding up???
I'm putting a SFA on a '96 GMC Jimmy. I plan to mount the shackles from the inside of the frame-rails. There is an existing hole in both sides of the frame that can be used to build off of. Basically, the hole is about 1/2" and a 1/2" OD piece of pipe will fit perfectly in the frame. Also, a 5/8" bolt will be a very close fit inside the 1/2" pipe, that when lubricated, would serve as a decent bushing. So, at this point, you are looking at a boxed frame, with a 1/2 pipe running through it, and welding in place with about .25" sticking out on both sides (for the weld bead). There is a 5/8" bolt passing through the pipe, flush with the outside, and sticking out about 5 or 6" on the inside. Now, it's time to hang the shackle. The shackle will be constructed from 2 flat-steel bars spaced apart just enough to sandwich the leaf-spring bushing. At one end of the shackle will be holes drilled for the spring bolts. At the other end will be 1/2" holes drilled to accept another 1/2" pipe, which will run through both steel bars, and welded from the inside. This will form basically an integral schackle/bushing assembly. Now, you are looking at the above image, but with the shackle and bushing slid onto the 5/8" bolt sticking out of the frame. The whole thing will be retained by 2 nuts tightened into each other. The idea here is to securely retain the bushing on the bolt, but allow just enough freeplay for it to rotate without grinding and binding on the other pipe in the frame.
Does this sound like a good way to build a bushing??? Does it matter that nothing is "rubber isolated" Can you buy pre-made shackles with bushings already pressed in??? When you tighten the bolt, what's to stop the whole thing from binding up???