Crankshaft and Bearings Cleaning and Inspection

Tools Required

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

Fig 1: Inspecting Crankshaft End Play
Courtesy of GENERAL MOTORS CORP.
1. Coat the crankshaft bearings with engine oil.
2. Install the upper crankshaft bearings into the engine block crankshaft journals.
3. Install the lower crankshaft bearings into the crankshaft bearing caps.
4. Install the crankshaft.
5. Inspect the crankshaft end play with the crankshaft bearings installed.
6. Check for permissible crankshaft end play. Refer to Engine Mechanical Specifications .
Fig 2: Checking Middle Crankshaft Journal For Out-Of-Round Runout
Courtesy of GENERAL MOTORS CORP.
7. With the crankshaft mounted on the front and rear crankshaft bearings, check the middle crankshaft journal for permissible out-of-round (runout). Refer to Engine Mechanical Specifications .
Fig 3: View Of Plastic Gauging Thread On Bearing
Courtesy of GENERAL MOTORS CORP.
IMPORTANT: Grease the crankshaft journals and lubricate the crankshaft bearings slightly so that the plastic gaging thread does not tear when the crankshaft bearing caps are removed.
8. Inspect all of the crankshaft bearing clearances using a commercially available plastic gaging (ductile plastic threads).
9. Cut the plastic gaging threads to the length of the bearing width. Lay them axially between the crankshaft journals and the crankshaft bearings.
Fig 4: View Of J 45059 And KM-470-B
Courtesy of GENERAL MOTORS CORP.
10. Install the crankshaft bearing caps.
NOTE: Refer to Fastener Notice .
11. Install the crankshaft bearing cap bolts using the J 45059  or the KM-470-B  .

    Tighten:  Tighten the crankshaft bearing cap bolts to 50 N.m (37 lb ft)  . Tighten the crankshaft bearing cap bolts 45 degrees plus 15 degrees.

Fig 5: Measuring Plastic Gaging
Courtesy of GENERAL MOTORS CORP.
12. Remove the crankshaft bearing caps.
13. Measure the width of the flattened plastic thread of the plastic gaging using a ruler. (Plastic gaging is available for different tolerance ranges.)
14. Inspect the bearing clearances for permissible tolerance ranges. Refer to Engine Mechanical Specifications .