vping said:
Just curious to know what it takes to rebuild any of the lever arm shocks that are on our cars.
I have a few minutes and can explain what's inside.
The usual failure is that the shock leaks at the shaft. If the shock loses enough oil from here, then problems occur inside with the pistons, etc. The ride becomes noticeable softer at this point. So the first thing to do is seal the shaft. The original "seal" is actually a 1/2" wide rubber packing retained in the shock by a steel washer that's crimped in the body. (the pic is of a Spridget front apart) Note that when the seal has leaked, that grit is likely to be attracted and score the shaft, so replacing the seal with the same kind wont last, and removing the old one will have damaged the retaining slot.
Regrettably, there are no oil seals made that are the correct size for the bore and shaft combination. There is one slightly smaller OD that some "rebuilders" mud in with silicone. The shaft will often be pitted and scored so that the seal will quickly wear, however. If the shock had been low on oil long enough, the surface that the shaft rotates in in the body will also have worn making a seal problematic. There is no bearing in the zinc body, originally.
Taking a front B apart is straight forward, push the shaft out. Taking a rear or other single arm apart is a little harder, as you should pull the arm and shaft together. (Drilling and pushing from the core plug side creates more problems) This requires some fixtures and hydraulics.
Once the shock is apart, you can give it a thorough cleaning and inspect for loose wristpins, and damaged poppet valves on the pistons. The main valve is the least problem, and usually just needs cleaning. Sometimes the piston bore will be scored from a loose wristpin, and needs to be sleeved.
I wont describe here what we do, but we overcome and address all of these issues, and more.
What you can try, and it's what I did on my first shock in 1972, is cram some rubber washers (garden hose style) in the bore and add a steel washer against the arm to hold them. Or what another "rebuilder" does is cram what looks like a thick tube-shock type mounting bushing in the hole. So long as the shaft isn't pitted, and the bearing surface is good, you may be able to successfully seal the shock. It's not what one might call a rebuild, but it might serve you for a while (and people do pay money for it).
Maybe I should do a proper write up for the Wiki?
Thanks for listening.
Peter C.