Low tech tips for mid 50's Buicks Part II: rear shocks

The front shocks were detailed in Part I , Now for the rear. Various vendors including CARS offer rebuilding service for rear shocks for about $230 a pair. I have no idea what they do when rebulding, but I could not stand to spend that much plus shipping when my shocks were functioning well, but leaking badly. So I took some shocks from a parts car and tried to remove the arm to get at the seal. None of the presses in my part of South Texas would move it, so I decided to get mean: some cutting and a big hammer. The following is not a rebuild, just seal replacement; the compression and rebound valves were removed as well as the top cover, but that part of the service is detailed in the shop manual.



Clamp the arm of the shock verically in a vise with the link end down and against the floor of the vise. This will make it more stable for later hammering.
A goove is cut in the shaft end of the arm almost to the the shaft and a small groove is cut into the end of the shaft to index with the arm when replaced. A large hammer and chisel is used to spread the groove slightly. After many tries the puller finally worked to remove the shaft.



Here are all of the tools displayed: Dremel tool, chisel, hammer, puller.



Parts are separated. Now to get the cup that serves as the seal retainer off the body. The cup is pressed to the body. I used increasingly larger chisels between the body and the cup to remove it.



The cup is off revealing the original seal which appears to be sponge rubber (now hard and crumbling).



After coating with silicone grease two O-rings were stacked on the shaft and the cup was installed and then staked in place with a center punch. I used some O-rings I had for the manifold of an air conditioner compressor. How do I know if this will work? I didn't at first on my first project but after 30,000 miles it is still dry.



The arms are pressed onto the shafts after drilling and tapping the shaft end of the arm and installing a socket head screw to clamp the arm to the shaft. Welding the groove in the arm would work also, but would require a good welder (machine and person) and I don't qualify. The screw method has worked well in the past and if the seal ever needs replacement, it would be easier in this case.



Painted and ready for installation.

If you remove the compression and rebound valves for inspection and cleaning, you need to refill the lower cylinders. Putting fluid in the reservior at the top will not get to the lower cylinders for a long time. After installing the rebound valve assembly (on the bottom), clamp the shock in a vise with the compression valve opening facing up. Add fluid slowly while moving the arm slowly until full and considerable resistance is felt. Install the compression valve assembly and then add fluid to the upper reservior. I use hydraulic jack oil with good results.

This procedure will not help of the shock is not functioning normally when full of fluid or if there is any movement between the shaft and the body.

Willie