GEAR TESTER / HYPOID GEAR LAPPER Make : GLEASON Model : 503 Maximum gear diameter : 266 mm. Maximum pinion diameter : 152 mm. Diameter of taper hole at large end : 100 mm. Taper / foot, depth of taper : 15 mm. Diameter of hole through spindle : 63 mm. Diameter of taper at large end : 58 mm. taper / foot : 13 mm. Depth of taper : 76 mm. Diameter of hole through spindle : 55 mm.