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Connecting Rod Bearing Selection

  1. Inspect each connecting rod for cracks and heat damage.

    Connecting Rod Big End Bore Code Locations 

  2. Each rod has a tolerance range from 0 to 0.024 mm (0.0009 in.), in 0.006 mm (0.0002 in.) increments, depending on the size of its big end bore. It's then stamped with a number or bar (1, 2, 3, or 4/I, II, III, or Mil) indicating the range. You may find any combination of numbers and bars in any engine. (Half the number or bar is stamped on the bearing cap, the other half is on the rod.)

    If you can't read the code because of an accumulation of oil and varnish, do not scrub it with a wire brush or scraper. Clean it only with solvent or detergent.

    Normal Bore Size: 51.0 mm (2.01 in.) 

    Fig 1: Identifying Connecting Rod Big End Bore Code Locations
    G05490182Courtesy of AMERICAN HONDA MOTOR CO., INC.

    Connecting Rod Journal Code Location 

  3. The connecting rod journal codes are stamped on the crankshaft.

    Connecting Rod Journal Code Location (Letters or Bars) 

    Fig 2: Identifying Connecting Rod Journal Code Location
    G05490183Courtesy of AMERICAN HONDA MOTOR CO., INC.
  4. Use the big end bore codes and rod journal codes to select appropriate replacement bearings from the following table.
    NOTE:
    • The color code is on the edge of the bearing.
    • When using bearing halves of different colors, it does not matter which color is used in the top or bottom.
      Fig 3: Identifying Big End Bore Codes And Rod Journal Codes
      G05490184Courtesy of AMERICAN HONDA MOTOR CO., INC.