Connecting Rod Bearing Clearance (With Micrometer Gauge Internal Measuring Device)

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Install the connecting rod bearings and the connecting rod bearing caps.
Tighten the connecting rod bearing caps bolts in the following sequence:
1. Tighten the connecting rod bearing cap bolts a first pass to 25 N.m (19 lb ft).
  CAUTION: Refer to Fastener Caution .
  
  CAUTION: Refer to Torque-to-Yield Fastener Caution .
  
  NOTE: The old bolts can be re-used for the measuring procedure.
2. Tighten the connecting rod bearing cap bolts a final pass to an additional 60 degrees, using the EN-45059 meter.
Measure the connecting rod bearing diameters at 3 points as shown (1), using an internal measuring device.

Fig 1: Measuring Connecting Rod Bearing Diameters
Courtesy of GENERAL MOTORS COMPANY
Calculate the average connecting rod inner diameter.
Formula: 1. result + 2. result + 3. result / 3
Measure the connecting rod journal diameter at 2 points between (1) and (3) and between (2) and (4), using a micrometer gauge.

Fig 2: Connecting Rod Journal Diameter Points
Courtesy of GENERAL MOTORS COMPANY
Calculate the average connecting rod journal diameter.
Formula: 1. result + 2. result / 2
Subtract the average connecting rod journal diameter from the average rod bearing diameter in order to determine the connecting rod bearing clearance.
For proper connecting rod clearance, refer to Engine Mechanical Specifications .