Measuring Piston Ring End Gap
WARNING: This page does not describe the selected car, but rather 6 other vehicles, including the 2004 GMC Yukon XL, 2004 GMC Yukon, 2004 Chevrolet Tahoe, 2004 Chevrolet Suburban, and 2004 Chevrolet Avalanche. However, it is still accessible from the selected car via links, so may be relevant.
- Do not attempt to file the end of the piston ring to achieve the proper end gap clearance.
- Measure the piston ring in the cylinder in which it will be used.
- Identify the NEW upper and lower compression rings. The upper compression ring can be identified by a paint mark (3) located 180 degrees from the end gap. The lower compression ring can be identified by a paint mark (3) located 90 degrees from the end gap. Both rings should be installed with the orientation marks (1, 2) facing the top of the piston.
- Place the piston ring into the cylinder bore 6.5 mm (0.25 in) below the top of the ring travel area.
- Insert a feeler gage and measure the piston ring end gap. 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) .
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