Using Sprocket Shaft As Gauge To Determine Bearing

Servicing Flywheels and Installing Crank Pin

First give attention to flywheel washers (24), Illus. 62 or 63. If washer in either flywheel is worn and grooved to any extent, it should be renewed. This hardened steel washer fits into recess in flywheel face around crank pin hole and takes side thrust of connecting rod lower end and bearing. Washer is a close fit in recess and is secured by punching flywheel metal tight against it at several points around outer edge of washer.

To remove washer, it is ordinarily necessary to drill a small hole {Ve" or smaller) at the outer edge of washer to permit getting a pointed tool underneath and prying it out. This hole should be small and should be drilled only to slightly greater depth than thickness of washer. Drilling hole too large or too deep weakens flywheel and it may crack at that point. Before installing new washer, scrape outer edge of recess where metal was punched against old washer and thoroughly clean recess, as new washer must seat fully against recess bottom. If washer is carelessly installed and does not seat fully in recess, female (forked) rod is not likely to have reguired sideplay when flywheels are assembled.

Crank pin can now be installed in right flywheel. Wipe pin taper and flywheel taper perfectly clean and free of oil. Be sure key is in place. Tighten nut very tight, using Harley-Davidson special, wrench, Part No. 11933-X. Install lock washer as it best matches lock screw hole—some washers can be installed either side up, others have two screw holes. If necessary, tighten nut a trifle more to make lock screw holes match. Install lock screw and tighten securely.

Check oil passage through pinion shaft, right flywheel and crank pin, with compressed air. Be sure this passage is open.

Truing and Sizing Connecting Rod Lower Races

In lapping a set of worn rods (use Harley-Davidson special lap. Part No. 11944-36), lap until no trace of wear shoulder is left at sides of roller path; also lap both rods to fit same size rollers.

When rod lower races are damaged or worn beyond truing up and refitting with largest oversize rollers, rods must be replaced with new or returned to factory for refitting with new lower races. It is not practical for other than the factory to renew these races as they are distorted considerably when pressed into rods and the initial truing must be done with a grinder; lap is intended only for smoothing up and resizing races, worn or not exactly the right size.

Turn lap in lathe 150 to 200 R.P.M. (see Illus. 50). When means of turning lap are not at hand, hold in vise and turn rod. Adjust lap to snug fit in race before applying lapping compound; a loose lap will "bell mouth" bearing race. Apply light coat of fine lapping compound. To avoid grooving or tapering lap, work rod back and forth along its full length.

New rods ordered from the factory or used rods returned to the factory for rebushing are usually ordered fitted with crank pin and rollers. If not, they are likely to need lapping to fit available rollers with specified clearance.

After it has been determined that lower end races are in good enough condition to be lapped and refitted, upper end bushings should be inspected for need of attention. Check bushings for looseness in rods as well as pin clearance (see "Installing and Fitting Connecting Rod Upper Bushing," Page 90).

Rods that have been returned to the factory for new lower end races will also be fitted with new upper end bushings, reamed to correct clearance for standard pin. This, of course, also applies to new rods.

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