Lapping Connecting Rod Races

Connecting rod lower races that are likely to clean up within the range of oversize bearing rollers and are otherwise in serviceable condition, should be trued and sized with Connecting Rod Lapping Arbor, Part No. 96740-36, as shown in Fig. 3E-9.

Turn lap in lathe at 150 to 200 rpm. Adjust lap by means of adjusting nut to a dragging but free fit in

Figure 3E-4. Pressing Flywheels Out of Crankcase rod race. Clean lap before using, then apply fine lapping compound (No. 220 grit grinding compound mixed with oil) to lap. A loose or tight lap will "bell mouth" bearing race so it must be kept adjusted at all times. To avoid grooving or tapering lapped surface in rod, work rod back and forth the full length of the lap holding rod as near race end as possible. Lap rods individually.

When rods are lapped true and all traces of pit marks or grooving are cleaned up, wash rods and blow dry. Surface should have a soft velvety appearance and be free of shiny spots. Assemble crank pin on right flywheel (see "Fitting Rod Bearings" before assembling flywheels). Wipe pin taper and flywheel taper perfectly clean and free from oil. Insert key in keyway and position flywheel over pin held in vise. Tighten nut very tight using Crank Pin and Flywheel Nut Wrench Part No. 94545-26. If necessary, tighten nut to make lock plate notches line up with corners of the nut with the lock washer screw hole in alignment. Never loosen nut to achieve this register. Never use length of pipe over handle of crank pin nut wrench. If a torque wrench is available tighten nuts to footpound reading as given in "Engine Specifications."

Assemble pinion shaft to right flywheel, with the Crank Pin and Flywheel Nut Wrench or TorqUe Wrench.

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