GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Chevrolet 🢒 2009 🢒 TrailBlazer - 2WD 🢒 Engine 🢒 Engine Mechanical - 4.2L 🢒 Cylinder Honing

    Warning: Refer to Safety Glasses Warning in the Preface section.


    Object Number: 186747 Size: SH
  1. When honing the cylinder bores, follow the manufacturer's recommendations for equipment use, cleaning, and lubrication.
    2. • Use only clean sharp stones of the proper grade for the amount of material to be removed.
    • Dull, dirty stones cut unevenly and generate excessive heat.
    • DO NOT hone to a final grade with a coarse or medium-grade stone.
    • Leave sufficient metal so that all the stone marks will be removed with the fine grade stones.
    • Perform the final honing with a fine-grade stone and hone the cylinder bore in a cross hatch pattern at 45-65 degrees to obtain the proper clearance.
  2. During the honing operation, thoroughly check the cylinder bore.
    3. • Repeatedly check the cylinder bore fit with the selected piston.
    • All measurements of the piston or cylinder bore should be made with the components at normal room temperature.
  3. When honing to eliminate taper in the cylinder bore, use full strokes the complete length of the cylinder bore.

    4. Repeatedly check the measurement at the top, the middle, and the bottom of the cylinder bore.

    • The finish marks should be clean but not sharp.
    • The finish marks should be free from imbedded particles or torn or folded metal.
  4. When finished, the reconditioned cylinder bores should have less than or meet the specified out-of-round and taper requirements.
  5. After the final honing and before the piston is checked for fit, clean the cylinder bore with hot water and detergent.
    6. 5.1. Scrub the cylinder bores with a stiff bristle brush.
    5.2. Rinse the cylinder bores thoroughly with clean hot water.
    5.3. Dry the cylinder bores with a clean rag.
    5.4.  Do not allow any abrasive material to remain in the cylinder bores.
            • Abrasive material may cause premature wear of the new piston rings and the cylinder bores.
            • Abrasive material will contaminate the engine oil and may cause premature wear of the bearings.
  6. Perform final measurements of the piston and the cylinder bore.
  7. Permanently mark the top of the piston for the specified cylinder to which it has been fitted.
  8. Apply clean engine oil to each cylinder bore in order to prevent rusting.