This is really a simple tool for compressing the springs on our shocks. I think this is the simplest, easiest, and cheapest spring compressor you can make for our cars.
Parts:
5/16" threaded rod
2 5/16" J-hooks with same thread as on the threaded rod (such as used for holding down a battery)
2 5/16" course threaded nuts (whatever thread is on the threaded rod and J-hooks)
2 5/16" washers - thick is probably better
2 5/16" threaded unions with same thread as the threaded rod, etc.
4 1/2" of 1/2" OD steel rod or tube (slightly smaller would be better)
The hardest part of this whole thing is going to be drilling the holes in the steel rod or tube. They should be bigger than 5/16" so the threaded rod that will go through them will be able to flop around a little. Mine are 11/32". They are 3 7/8" apart. The reason for that is that will help keep the threads from the threaded rod from scarfing up the spring.
I put liquid plastic goo used to cushion pliers, etc. on the 'J' part of the J-hooks to protect the springs. A piece of rubber tubing would probably be better.
I think assembly and use are pretty straightforward.
I'm sure you can get a lot fancier and nicer but for those who are in the "chisel and file" level of fabrication, this works great.
If you have a solution for compressing road springs, feel free to post it here!