Truing And Sizing Main Bearing Races

securely tightened as in final assembly; this is to assure perfect alignment between left and right races in assembly. Lap first one side and then the other, guiding lap by means of pilot bushing in opposite race. Adjust lap snugly in race and use only a light application of fine lapping compound. A loose lap and the use of excessive amount of compound results in tapered bearing surface.

Fitting Main Bearings

When fitting main bearings, the shafts that are to be used when flywheels are reassembled can be used as gauges (see Illus. 49) with which to determine when bearings are fitted to correct clearance. Use the largest roller size that will allow shaft just noticeable shake in bearing. Bearing must not be fitted so tight that shaft has no shake at all. In making this check, all bearing parts must be perfectly clean and dry; oil in the bearing will take up some clearance and make bearing feel tighter than it is actually fitted. Sprocket shaft clearance in left main bearing should be .0005" to .001"; pinion gear shaft clearance in right main bearing should be .0008" to .0012".

After main bearing fitting is completed, crankcases with roller and retainer assembly can be set aside until flywheels are assembled.

Mainshafts can now be installed to their respective flywheels, sprocket shaft to left (heavier) flywheel, pinion gear shaft to right (lighter) flywheel. Wipe shaft tapers and flywheel tapers perfectly clean and free of oil. Be sure keys are in place. Tighten nuts very tight, using Harley-Davidson special wrench. Part No. 11933-X. Install lock washers. Lock washer can be installed either side up as it best matches lock screw hole. If necessary, tighten nut a trifle more to make iock screw holes match. Install lock screw and tighten securely.

After right side (pinion gear) shaft is installed check oil passage through shaft and side of flywheel with compressed air, to be sure passage is open.

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