Crankshaft Main Bearing Journal Clearance

Check 

• 1.
  
  
  NOTE: Crankshaft main bearing journals must be within specifications before checking journal clearance.

  Remove the crankshaft main bearing cap and crankshaft main bearing.

• 2.
  
  Position a piece of Plastigage across the crankshaft main bearing surface.

Courtesy of FORD MOTOR COMPANY

• 3.
  
  
  NOTE: Do not turn the crankshaft while carrying out this procedure.

  Install and tighten to specifications, then remove the crankshaft main bearing cap.

• 4.
  
  Measure the Plastigage to get the crankshaft main bearing clearance. The Plastigage should be smooth and flat. A changing width indicates a tapered or damaged crankshaft or crankshaft bearing.

Courtesy of FORD MOTOR COMPANY