Gear shift fork insert

A shifting mechanism in an automotive transmission comprising a shift element supported on a longitudinally extending main shaft of the transmission and a fork body supported on a fork shaft having its axis parallel to said main shaft for axial travel thereon, said fork body having a pair of downwardly extending branch ends, each said branch end supporting an insert thereon formed of synthetic resin material, each said insert engaging a circumferential groove in said shift element for shifting the transmission, said groove having a channel-shape defined by a cylindrical base surface and a pair of opposed transverse side thrust surfaces, the improvement in said shifting mechanism comprising:

• said fork a body having a metal plate member formed with a pair of branch planar ends, said branch planar ends having inboard opposed vertical clearance faces formed with mirror image rectangular-shaped notches, each said notch having an open side, parallel opposed upper and lower end flanks, and a back side having a predetermined transverse depth relative to its associated clearance face;
• each said insert having a pair of vertically elongated fore and aft mirror image opposing axially spaced walls, said walls separated by a rectangular spacer block providing a uniform predetermined axial space therebetween, said spacer block positioned intermediate upper and lower ends of said pair of walls and adapted for fixed conforming reception in an associated one of said notches, each said insert pair of walls two opposite outside thrust faces and two opposing inside wall faces with said pair of side walls defining a pair of inboard elongated bearing edges;
• said spacer block having axial ends each integrally joined to an associated insert inside wall surface, said spacer block having a radially outboard indented stop wall and an opposite radially inboard flush wall coplanar with its associated inboard bearing edges, said spacer block indented stop wall spaced from said spacer block flush wall be a dimension greater than its associated notch depth providing a predetermined differential dimension therebetween;
• whereby upon insertion of each said insert spacer block fixed in its associated notch its indented stop wall engages its associated notch back side such that its pair of side wall bearing edges are raised above their associated clearance face by reason of said predetermined differential dimension wherein each said pair of insert bearing edges provide the sole contact with said groove cylindrical base surface obviating metal-to-metal contact between each said fork clearance face and said groove base.