LEMON Manuals: Even more car manuals for everyone
Home >> GMC >> 2003 >> Safari Van Cargo, AWD >> Repair and Diagnosis >> External Pages >> Different car >> Section 1030 (Engine Mechanical - 4.8L, 5.3L & 6.0L (Repair Instructions - 2 Of 3)) >> Repair Instructions (Off-Vehicle Repair Instructions Part 2) >> Piston, Connecting Rod, and Bearings Cleaning and Inspection >> Connecting Rod and Bearings

Connecting Rod and Bearings

WARNING: This page is about a different car, the 2004 GMC Sierra, 2004 GMC Cab & Chassis Sierra, 2004 Chevrolet Silverado, and 2004 Chevrolet Cab & Chassis Silverado. However, it is still accessible from the selected car via links, so may be relevant.
    IMPORTANT:
    • The powdered metal connecting rod and cap are machined for proper clearances. The connecting rod and cap must be used as an assembly with no repair or modifications to either mating surface. Do not attempt to repair the rod or cap. If service is required, replace the first design press-fit piston, pin, and connecting rod as an assembly.
    • Do not attempt to repair the bolt hole threads of the connecting rod.
  1. Clean the connecting rod (2) and cap (4) in solvent.
    2. Fig 1: View Of Piston & Connecting Rod Components
    GM1366359Courtesy of GENERAL MOTORS CORP.
    CAUTION: Wear safety glasses in order to avoid eye damage.
  2. Dry the components with compressed air.
  3. Inspect the connecting rod for the following conditions:
    • Twisting (1)
    • Proper fit of the connecting rod and cap mating surfaces (2)
    • Nicks or gouges in the bearing bore (3)
    • Damage to the bearing locating slots (4)
    4. Fig 2: Identifying Connecting Rod Inspection Areas
    GM1366360Courtesy of GENERAL MOTORS CORP.
  4. Measure the connecting rod bearing bore (1) for an out-of-round condition. Refer to Engine Mechanical Specifications (LR4 VIN V) or Engine Mechanical Specifications (LM7 VIN T) or Engine Mechanical Specifications (L59 VIN Z) or Engine Mechanical Specifications (LQ4 VIN U) or Engine Mechanical Specifications (LQ9 VIN N) .
    5. Fig 3: View Of Connecting Rod Bearing Bore
    GM1366406Courtesy of GENERAL MOTORS CORP.
  5. To determine full-floating piston pin-to-connecting rod bore clearance, use a micrometer and measure the piston pin outside diameter (OD).
    6. Fig 4: Measuring Piston Pin Diameter
    GM4976Courtesy of GENERAL MOTORS CORP.
  6. To determine the full-floating piston pin-to-connecting rod bore clearance, use a micrometer and measure the connecting rod pin bore (1) inside diameter (ID).
    7. Fig 5: Measuring Connecting Rod Pin Bore Inside Diameter
    GM1366411Courtesy of GENERAL MOTORS CORP.
  7. Subtract the piston pin OD measurement from the connecting rod pin bore ID measurement to determine pin-to-bore clearance. Refer to Engine Mechanical Specifications (LR4 VIN V) or Engine Mechanical Specifications (LM7 VIN T) or Engine Mechanical Specifications (L59 VIN Z) or Engine Mechanical Specifications (LQ4 VIN U) or Engine Mechanical Specifications (LQ9 VIN N) .
  8. Inspect the connecting rod bearings for craters or pockets. Flattened sections on the bearing halves indicate fatigue.
    9. Fig 6: Identifying Crankshaft Bearing Craters Or Pockets
    GM52051Courtesy of GENERAL MOTORS CORP.
  9. Inspect the connecting rod bearings for excessive scoring or discoloration.
  10. Inspect the connecting rod bearings for dirt or debris imbedded into the bearing material.
    11. Fig 7: Identifying Connecting Rod Bearing Scoring Or Discoloration
    GM52053Courtesy of GENERAL MOTORS CORP.
  11. Inspect the connecting rod bearings for improper seating indicated by bright, polished sections of the bearing surface.
    12. Fig 8: Crankshaft Bearing Polished Sections (Improper Seating)
    GM52056Courtesy of GENERAL MOTORS CORP.
scientia non olet · About LEMON Manuals