Main Bearing Oil Clearance

Method by Calculation 

• Install main bearings (3) to cylinder block (1) and main bearing cap (2), and tighten main bearing cap bolts to the specified torque. Refer to Disassembly and Assembly  for the tightening procedure.

  Courtesy of NISSAN NORTH AMERICA, INC.

• Measure the inner diameter of main bearing with a bore gauge.

(Oil clearance) = (Main bearing inner diameter) - (Crankshaft main journal diameter)

• If the calculated value exceeds the limit, select proper main bearing according to main bearing inner diameter and crankshaft main journal diameter to obtain the specified bearing oil clearance. Refer to Description .

Method of Using Plastigage 

• Remove engine oil and dust on crankshaft journal and the surfaces of each bearing completely.
• Cut a plastigage slightly shorter than the bearing width, and place it in crankshaft axial direction, avoiding oil holes.
• Install main bearing to cylinder block and main bearing cap, and tighten main bearing cap bolts with main bearing cap to the specified torque. Refer to Disassembly and Assembly  for the tightening procedure.
  CAUTION: Do not rotate crankshaft.
• Remove main bearing cap and bearings, and using the scale on the plastigage bag, measure the plastigage width.

  Courtesy of NISSAN NORTH AMERICA, INC.

  NOTE: The procedure when the measured value exceeds the limit is the same as that described in the "Method by Calculation".