Figure 4-47. Crankshaft, Removal/Installation.

TM 55-1930-208-24

(10) Remove oil slinger (5) and then use a gear puller and remove gear (6) and key (7).

Figure 4-47. Crankshaft, Removal/Installation.

b. Cleaning.

(1) After the crankshaft has been removed, clean and inspect it thoroughly before re stalling it in the engine.

(2) Remove the plugs and clean out the oil passages thoroughly with a stiff wire brush. Clean the crankshaft with

fuel oil (item 9, Appendix C) and allow it to dry. Then reinstall the plugs.

c. Inspection.

(1) Inspect keyways for evidence of cracks or wear. Replace the crankshaft, if necessary.

(2) If the crankshaft shows evidence of excessive overheating, replace the crankshaft since the heat treatment

has probably been destroyed.

(3) Used crankshafts will sometimes show a certain amount of ridging caused by the groove in the upper main

bearing shell or lower connecting rod bearing shell. Ridges exceeding .0002 inch must be removed. If the

ridges are not removed, localized high unit pressure on new bearing shells will result during engine operation.

(4) The ridges may be removed by working crocus cloth, wet with fuel oil, around the circumference of the

crankshaft journal. If the ridges are greater than .0005 inch, first use 120 grit emery cloth (item 7, Appendix

C) to clean up the ridge, 240 grit emery cloth (item 7, Appendix C) for finishing and wet crocus cloth (item 5,

Appendix C) for polishing. Use of a piece of rawhide or other suitable rope wrapped around the emery cloth

(item 7, Appendix C) or crocus cloth (item 5, Appendix C) and drawn back and forth will minimize the

possibility of an out-of-round condition developing (keep the strands of rawhide apart to avoid bind). If

rawhide or rope is not used, the crankshaft should be rotated at intervals. If the ridges are greater than .001

inch, the crankshaft must be replaced.

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