There are two types of serviceable shifter bushings:

  • Seat washer at fulcrum point inside OE housing of most Toyota & Aisin AX trans
    • OE shifters only, application-specific
    • Unique to Toyota & Aisin; most other OE shifters are not serviceable like this
  • Lower bushing / pivot cup / insulator / isolator where shift lever engages internal rail of most Tremec, New Venture, Aisin, Toyota, & Nissan trans
    • Used by OE & aftermarket, mostly generalized by transmission model

In both cases, shift lever contacts bushing with a spherical interface and bushing sits within a cylindrical bore. As such, they are defined by diameter of lever sphere and diameter of housing bore. There is also a saddle-type bushing used by late '70s SR4 & SROD trans but fairly obscure today. Some shifters use a direct metal-on-metal interface with trans, usually w/ sides of stub milled flat (NV4500, M5OD) and shifter stub must be replaced when worn