HOUSING-PUMP 4P3681 - Caterpillar

(1) Rack bearing alignment - the center of the rack bearing tab must be within .002 in. (0.05 mm) of a vertical line that: (a) goes through the center of the rack bearing(b) is parallel to the vertical centerline thru the injection pump bores and camshaft bearing bores. The following tools are available to position the rack bearings correctly: 5P1744 Plate and 9S6329 Driver.The correct bearing depth is controlled when driver is stopped by plate.(2) Install pins until they contact bottom of housing casting.(3) Install plug flush with casting surface.(4) Install rear rack bearing to a depth of ... .282 .005 in.(7.16 0.13 mm) Small holes in bearing must be positioned as shown (parallel to the vertical centerline thru the pump).(5) Install dowel to get a dimension from centerline of fuel injection pump bore to dowel (seal dowel hole with aluminum ball) ... .584 .002 in.(14.83 0.05 mm)(6) Bore in bearings for the camshaft (new) ... 2.1255 .0015 in.(53.988 0.038 mm) Diameter of bearing surfaces of the camshaft (new) ... 2.1220 .0005 in.(53.899 0.013 mm)Maximum permissible clearance between the bearings and the camshaft ... .010 in.(0.25 mm)(7) Install front and rear camshaft bearing flush with front of housing.(8) Distance from rear face of housing to installed center camshaft bearing ... 4.81 .02 in.(122.2 0.5 mm)(9) Distance from rear of housing to end of dowel ... .62 .02 in.(15.7 0.5 mm)(10) Position of camshaft bearing joints must be limited to area (A) (from vertical centerline ... 15°