Crankshaft Inspection: Notes

Out-of-Round and Taper 

1. Remove the crankshaft from the engine block (see CRANKSHAFT AND PISTON REMOVAL ).
2. Clean the crankshaft oil passages with pipe cleaners or a suitable brush.
3. Clean the keyway and threads.
4. Measure the out-of-round at the middle of each rod and main journal in two places. The difference between measurements on each journal must not be more than the service limit.

   Journal Out-of-Round 

   Standard (New): 0.004 mm (0.0002 in.) max. 

   Service Limit: 0.010 mm (0.0004 in.) 

   Fig 1: Identifying Journal Out-Of-Round

   Courtesy of AMERICAN HONDA MOTOR CO., INC.
5. Measure the taper at the edges of each rod and main journal. The difference between measurements on each journal must not be more than the service limit.

   Journal Taper 

   Standard (New): 0.005 mm (0.0002 in.) max. 

   Service Limit: 0.010 mm (0.0004 in.) 

   Straightness 

6. Place the engine block on the surface plate.
7. Clean and install the bearings on the No. 1 and No. 5 journals of the engine block.
8. Lower the crankshaft into the block.
9. Measure runout on all main journals. Rotate the crankshaft two complete revolutions. The difference between measurements on each journal must not be more than the service limit.

   Crankshaft Total Runout 

   Standard (New): 0.02 mm (0.0008 in.) max. 

   Service Limit: 0.04 mm (0.0016 in.) 

Fig 2: Measuring Main Journals Runout

Courtesy of AMERICAN HONDA MOTOR CO., INC.