Join Date: Nov 2011
Location: Lexington, Kentucky, USA
Year: 1982 - All Three
Make: Aspy, Interstate, Naked
The stock GL1100 and GL1200 shocks are Showa air-over shocks. The "shock" part of the rear assemble is "not" serviceable. It is a welded closed unit containing the piston, sleeve, compression and extension dampening valves. The GL1100 shock contains a rubber bumper stop on the shaft that cushions full compression. This is what causes a great deal of shock failures but can be remedied.
During my rebuild I found the rubber bump stop deteriorated. It appears not to be compatible with long exposure to oil. I also determined one of my shocks was not dampening on the compression stroke.
So... I wanted to investigate what actually failed and was surprised it wasn't wear of the internal components, it was the deterioration of the rubber bumper...
This is a picture of my shock, ground the cap off, and disassembled the components.