The Gs400e 1978 (c) (e01 E02 E04 E17 E18 E21 E22 E24 E25 E30 E34 E39 Special Market (e18) (gs400n:f.no.71032~) (gs400en:f.no. consists of twenty-five pieces with the Tube,inner being the most expensive.
In this schematic the "Spacer,oil Seal" is used most often.