Usage:
3406, 3408 Engines In All Applications
During repairs, some servicemen have installed new rubber vibration dampers on engine crankshafts because of wobble (movement to the front and then to the rear during rotation) on the outer ring of the used damper. In many cases this replacement was not necessary. Some wobble on the outer ring is normal.
Current Service Manuals do not give a maximum permitted measurement for this wobble. A maximum permitted tolerance will be added to the Service Manual at a later date. Until that time, use the procedure that follows to measure the wobble of the damper on the engine.
1. Install a dial indicator, contact point and other parts as needed to hold the dial indicator stationary. The contact point must be perpendicular (at 90° angle) to the face of the outer ring of the damper and must make contact approximately at the center of the outer ring.
2. Push on the end of the crankshaft so the end play (free movement on the centerline) is removed. Keep the crankshaft pushed back until the measurements are done.
3. Adjust the dial indicator to zero.
4. Turn the crankshaft 360° and watch the dial indicator. A total indicator reading of .080" (2.03 mm) or less is acceptable.