Home » 2008 6.6L Duramax » 2008 6.6L Duramax – PISTON, CONNECTING ROD, AND BEARING CLEANING AND INSPECTION

2008 6.6L Duramax – PISTON, CONNECTING ROD, AND BEARING CLEANING AND INSPECTION

1. Clean the deposits from the following components:

• Scoring in the piston pin area (3)
• Cracks (1)
• Broken ring groove lands

3. Measure the piston ring end gap.
• Use a piston to square the piston ring near the top o f the cylinder.
• Use a feeler gauge to measure the piston ring gap.
• The 1st compression ring production gap is 0.30-0.45 mm (0 .0 1 1 8 -0 .0 1 7 7 in) and the service limit is 1.37 mm     (0 .0 539 in).
• The 2nd compression ring production gap is 0.50-0.65 mm (0.019 7 -0 .0 2 5 6 in) and the service limit is 1.35 mm     (0.0531 in).
• The oil ring production gap is 0.15-0.35 mm (0.005 9 -0 .0 1 3 8 in) and the service limit is 1.20 mm (0.0472 in).
• Replace the piston ring if the measured value exceeds the service limit.

4. Measure the piston ring to piston ring groove clearance.

• Use a feeler gauge to measure the clearance between the piston ring and the piston ring groove at several points           around the piston.
• The 1st compression ring production clearance is 0.08-0.17 mm (0 .0 0 3 0 -0 .0 0 0 7 in) and the service limit is         0.26 mm (0.0102 in).
• The 2nd compression ring production clearance is 0.01-0.03 mm (0 .0004-0.0012 in) and the service limit is 0.10       mm (0.0039 in).
• The oil ring production clearance is 0.01-0.03 mm (0.0004 -0 .0 0 1 2 in) and the service limit is 0.12 mm (0 .0 0 4     7 in).
• Replace the piston ring if the measured value exceeds the service limit.

5. Measure the piston pin outside diameter.

• Measure the piston pin outside diameter at several points.
• The production value is 3 4 .4 95-34.50 nun (1.3581-1.3563 in) and the service limit is 34.450 mm (1.3563 in).
• Replace the piston pin if the measured value is less than the service limit.

6 . Measure the piston pin to piston pin bore clearance.
• Measure the piston pin bore.

• Subtract the piston pin measurement that was taken previously from the piston pin bore measurement. The                difference between these two measurements will be the piston pin to piston pin bore clearance.
• The production clearance is 0.004-0.017 mm (0 .0 0 0 2 -0 .0 0 0 7 in) and the service limit is 0.017 mm (0 .0 0 0       7  in).
• If the piston pin to piston pin bore clearance is beyond specifications then replace the piston.

7. Measure the piston pin to connecting rod small end clearance.
• Measure the inside diameter o f the connecting rod small end.
• Subtract the piston pin measurement that was taken previously from the connecting rod small end measurement.       The difference between these two measurements will be the piston pin to connecting rod clearance.
• The production clearance is 0.012-0.027 mm (0.0005-0.0011 in) and the service limit is 0.08 mm (0.0031 in).
• Replace the connecting rod if the piston pin to connecting rod small end clearance is beyond specifications. The           connecting rod small end bushing is not serviceable.