Chevrolet Silverado / GMC Sierra. Service manual — part 2121

distorted piston ring, replace the rings, as required.

Fig. 33: Measuring Piston Ring Side Clearance
Courtesy of GENERAL MOTORS CORP.

7. Measure the piston ring side clearance with a feeler gage. If side clearance is not within

specifications, try another piston ring. If the proper ring-to-groove clearance cannot be
obtained, replace the piston and pin as an assembly. Refer to Engine Mechanical
Specifications (RPO LY5 VIN J) or Engine Mechanical Specifications (RPO LC9
VIN 3) or Engine Mechanical Specifications (RPO LY2 VIN C) or Engine
Mechanical Specifications (RPO LH6 VIN M) or Engine Mechanical Specifications
(RPO LMG VIN 0) or Engine Mechanical Specifications (RPO LY6 VIN K) or
Engine Mechanical Specifications (RPO L76 VIN Y) or Engine Mechanical
Specifications (RPO L92 VIN 8) .

2008 Chevrolet Silverado 1500

2008 ENGINE Engine Mechanical - 4.8L, 5.3L, 6.0L, 6.2L, or 7.0L - Cab & Chassis Sierra, Cab & Chassis Silverado,

Sierra & Silverado

Fig. 34: Measuring Piston Pin Diameter
Courtesy of GENERAL MOTORS CORP.

8. To determine piston pin-to-bore clearance, use a micrometer and measure the piston pin

outside diameter (OD).

2008 Chevrolet Silverado 1500

2008 ENGINE Engine Mechanical - 4.8L, 5.3L, 6.0L, 6.2L, or 7.0L - Cab & Chassis Sierra, Cab & Chassis Silverado,

Sierra & Silverado

Fig. 35: Measuring Piston Pin-To-Bore Clearance
Courtesy of GENERAL MOTORS CORP.

9. To determine the piston pin-to-bore clearance, use an inside micrometer and measure the

piston pin bore inside diameter (ID).

10. Subtract the piston pin OD measurement from the piston pin bore ID measurement to

determine pin-to-bore clearance. Refer to Engine Mechanical Specifications (RPO LY5
VIN J) or Engine Mechanical Specifications (RPO LC9 VIN 3) or Engine Mechanical
Specifications (RPO LY2 VIN C) or Engine Mechanical Specifications (RPO LH6
VIN M) or Engine Mechanical Specifications (RPO LMG VIN 0) or Engine
Mechanical Specifications (RPO LY6 VIN K) or Engine Mechanical Specifications
(RPO L76 VIN Y) or Engine Mechanical Specifications (RPO L92 VIN 8) .

Measuring Piston Ring End Gap

2008 Chevrolet Silverado 1500

2008 ENGINE Engine Mechanical - 4.8L, 5.3L, 6.0L, 6.2L, or 7.0L - Cab & Chassis Sierra, Cab & Chassis Silverado,

Sierra & Silverado

Fig. 36: Measuring Piston Ring End Gap
Courtesy of GENERAL MOTORS CORP.

IMPORTANT:

Do not attempt to file the end of the piston ring to
achieve the proper end gap clearance.

2008 Chevrolet Silverado 1500

2008 ENGINE Engine Mechanical - 4.8L, 5.3L, 6.0L, 6.2L, or 7.0L - Cab & Chassis Sierra, Cab & Chassis Silverado,

Sierra & Silverado