Piston, Connecting Rod, and Bearings Cleaning and Inspection

Tools Required

• J 45059  Angle Meter
• KM-470-B  Angular Torque Gage

Fig 1: View Of Plastigage On Journal
Courtesy of GENERAL MOTORS CORP.
CAUTION: Refer to Safety Glasses Caution .
1. Coat the connecting rod bearings with engine oil.
2. Install the upper connecting rod bearings into the connecting rod journals.
3. Install the lower connecting rod bearings into the connecting rod bearing caps.
IMPORTANT: Grease the connecting rod journals and lubricate the connecting rod bearings slightly so that the plastic gaging thread does not tear when the connecting rod bearing caps are removed.
4. Measure all of the connecting rod bearing clearances using a commercially available plastic gaging, ductile plastic threads.
5. Cut the plastic gaging threads (1) to the length of the bearing width. Lay them axially between the connecting rod journals and the connecting rod bearings.
Fig 2: Using J 45059 Or KM-470-B To Torque Rod Bolts
Courtesy of GENERAL MOTORS CORP.
6. Install the connecting rod bearing caps.
7. Install the connecting rod bearing cap bolts.

   Tighten:  Tighten the connecting rod bearing cap bolts to 35 N.m (26 lb ft)  . Using the J 45059  or the KM-470-B  (1), tighten the connecting rod bearing cap bolts plus 45 degrees plus 15 degrees.

Fig 3: Measuring Plastigage
Courtesy of GENERAL MOTORS CORP.
8. Remove the connecting rod bearing caps.
9. Measure the width of the flattened plastic thread (1) of the plastic gaging using the scale printed on the plastic gaging package. Plastic gaging is available for different tolerance ranges.
10. Inspect the bearing clearance for permissible tolerance ranges. Refer to Engine Mechanical Specifications .