TM-9-2815-200-35 Maintenance Manual for AVDS-1790-2M AVDS-1790-2A and AVDS-1790-2AM Engines Download
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Figure 4-80 1. Using two 5 / 16-in. steel rods (A), hold fuel injection pump drive coupler sleeve (nearest the pump) stationary and rotate the other drive coupler sleeve counterclockwise to remove backlash from the pump drive shaft. 2. When backlash is removed and flat sides of drive coupler mate, tighten four drive coupler bolts (B) securely. 3. When flat sides of drive coupler sleeves (C) do not mate when backlash is removed, the coupler sleeves must be separated and reset. Separate coupler and push sleeve of drive coupler on rear fan and accessory drive housing (fig. 4-75) shaft toward drive shaft and from hub splines. Adjust sleeve on splines so flat sides of coupler half are alined. Torque tighten coupler bolts. Lubricate drive coupler (fig. 4-80). Figure 4-79. Removing fuel injection pump drive gear train backlash and setting advanced unit retard position-splined coupler. 4-40 Note. For proper assembly of coupler half to diaphragm pack, place a pry bar between rear fan and accessory drive housing and coupler half and apply pressure to take up the end thrust of drive gear. Measure clearance between coupler half and diaphragm pack. This clearance cannot exceed 0.050-inch or it will put undue stress on the diaphragm pack causing early failure. If the 0.050-inch dimension cannot be achieved, it will be necessary to remove fuel injection pump and replace coupler hall or complete coupling assembly. Torque coupler half retaining nut to 900 inch-pounds when installing new coupler half. Figure 4-81. Checking diaphragm coupler assembly clearance.