Chevrolet Silverado / GMC Sierra. Manual - part 411
Fig. 46: View Of Drive Belt Tensioner
Courtesy of GENERAL MOTORS CORP.
1. Remove the drive belt. Refer to Drive Belt Replacement .
2. Position a 3/8-inch drive breaker bar into the drive belt tensioner opening and rotate the
tensioner counterclockwise.
3. Move the drive belt tensioner through its full travel.
NOTE:
Allowing the drive belt tensioner to snap into the free position
may result in damage to the tensioner.
IMPORTANT: When the engine is operating the drive belt tensioner arm
will move. Do not replace the drive belt tensioner because of
movement in the drive belt tensioner arm.
2008 Chevrolet Silverado 1500
2008 ENGINE Engine Mechanical - 6.6L - Cab & Chassis Sierra, Cab & Chassis Silverado, Sierra & Silverado
The movement should feel smooth
There should be no binding
The tensioner should return freely
4. If any binding is observed, replace the drive belt tensioner. Refer to Drive Belt Tensioner
Replacement .
5. Install the drive belt. Refer to Drive Belt Replacement .
DESCRIPTION AND OPERATION
DRIVE BELT SYSTEM DESCRIPTION
The drive belt system consists of the following components:
The drive belt
The drive belt tensioner
The drive belt idler pulley
The crankshaft balancer pulley
The accessory drive component mounting brackets
The accessory drive components
The power steering pump, if belt driven
The generator
The A/C compressor, if equipped
The engine cooling fan, if belt driven
The water pump, if belt driven
The vacuum pump, if equipped
The air compressor, if equipped
The drive belt system may use 1 belt or 2 belts. The drive belt is thin so that it can bend
backwards and has several ribs to match the grooves in the pulleys. The drive belts are made of
different types of rubbers, chloroprene or EPDM, and have different layers or plys containing
either fiber cloth or cords for reinforcement.
Both sides of the drive belt may be used to drive the different accessory drive components. When
the back side of the drive belt is used to drive a pulley, the pulley is smooth.
The drive belt is pulled by the crankshaft balancer pulley across the accessory drive component
pulleys. The spring loaded drive belt tensioner keeps constant tension on the drive belt to prevent
2008 Chevrolet Silverado 1500
2008 ENGINE Engine Mechanical - 6.6L - Cab & Chassis Sierra, Cab & Chassis Silverado, Sierra & Silverado
the drive belt from slipping. The drive belt tensioner arm will move when loads are applied to the
drive belt by the accessory drive components and the crankshaft.
The drive belt system may have an idler pulley, which is used to add wrap to the adjacent pulleys.
Some systems use an idler pulley in place of an accessory drive component when the vehicle is
not equipped with the accessory.
ENGINE COMPONENT DESCRIPTION
Engine Block
2008 Chevrolet Silverado 1500
2008 ENGINE Engine Mechanical - 6.6L - Cab & Chassis Sierra, Cab & Chassis Silverado, Sierra & Silverado
Fig. 47: Identifying 6.6L Cylinder Locations
Courtesy of GENERAL MOTORS CORP.
The engine block utilizes a deep skirt design for increased rigidity. The cylinders are positioned
in a 90 degree "V" orientation with the number one cylinder being the right front. The block is
induction hardened for increased durability. The crankshaft bearing caps are cross-bolted to
enhance structural rigidity.
Upper Oil Pan
2008 Chevrolet Silverado 1500
2008 ENGINE Engine Mechanical - 6.6L - Cab & Chassis Sierra, Cab & Chassis Silverado, Sierra & Silverado