Visual Inspection

Camshaft Sprockets

Fig 1: View of Left Camshaft Sprockets
Courtesy of GENERAL MOTORS CORP.
1. Inspect the front of the left exhaust and intake camshaft sprockets for the following:
   • Sprocket damage (1)
   • Camshaft locating pin hole damage (2)
   • Mounting bolt hole damage (3)
Fig 2: Inspecting Left Camshaft Sprockets
Courtesy of GENERAL MOTORS CORP.
2. Inspect the back of the left exhaust and intake camshaft sprockets for the following:
   • Sprocket damage (1)
   • Camshaft locating pin hole (2)
   • Camshaft seating/sealing inner hub flange damage (3)
Fig 3: Inspecting Front of Right Intake Camshaft Sprocket
Courtesy of GENERAL MOTORS CORP.
3. Inspect the front of the right exhaust camshaft sprocket for the following:
   • Sprocket damage (1)
   • Camshaft locating pin hole damage (2)
   • Mounting bolt hole damage (3)
Fig 4: Inspecting Back of Right Intake Camshaft Sprocket
Courtesy of GENERAL MOTORS CORP.
4. Inspect the back of the right exhaust camshaft sprocket for the following:
   • Sprocket damage (1)
   • Camshaft locating pin hole (2)
   • Camshaft seating/sealing inner hub flange damage (3)
Fig 5: View Of Front Of Right Intake Camshaft Sprocket
Courtesy of GENERAL MOTORS CORP.
5. Inspect the front of the right intake camshaft sprocket for the following:
   • Sprocket damage (1)
   • Camshaft locating pin hole damage (2)
   • Mounting bolt hole damage (3)
   • Camshaft position sensing features (4)
Fig 6: View Of Back Of Right Intake Camshaft Sprocket
Courtesy of GENERAL MOTORS CORP.
6. Inspect the back of the right intake camshaft sprocket for the following:
   • Sprocket damage (1)
   • Camshaft locating pin hole (2)
   • Camshaft seating/sealing inner hub flange damage (3)
7. Replace a damaged camshaft position actuator.

Intermediate Sprocket

Fig 7: Inspecting Front Of Intermediate Sprocket
Courtesy of GENERAL MOTORS CORP.
1. Inspect the front of the intermediate sprocket for the following:
   • Sprocket damage (1)
   • Bearing bore damage (2)
   • Thrust surface damage (3)
Fig 8: Inspecting Back Of Intermediate Sprocket
Courtesy of GENERAL MOTORS CORP.
2. Inspect the back of the intermediate sprocket for the following:
   • Sprocket damage (1)
   • Bearing bore damage (2)
   • Thrust surface damage (3)
3. Replace a damaged intermediate sprocket.

Crankshaft Sprocket

Fig 9: Inspecting Intermediate Sprocket
Courtesy of GENERAL MOTORS CORP.
1. Inspect the intermediate sprocket for the following:
   • Sprocket damage (1)
   • Bore damage (2)
   • Keyway damage (3)
2. Replace a damaged crankshaft sprocket.

Primary and Secondary Timing Chains

Fig 10: Inspecting Primary And Secondary Timing Chains With Roller Chain
Courtesy of GENERAL MOTORS CORP.
1. Inspect the primary and/or secondary timing chain for the following:
   • Binding or worn rollers (1)
   • Loose links (2)
   • Loose pins (3)
2. Replace a damaged primary and/or secondary timing chains.

Primary Timing Chain Guide

Fig 11: Inspecting Primary Timing Chain Guide
Courtesy of GENERAL MOTORS CORP.
1. Inspect the primary timing chain guide for the following:
   • Worn guide surface (1)
   • Cracked or broken guide surface (2)
   • Cracked or damaged guide base (3)
2. Replace a damaged primary timing chain guide.

Secondary Timing Chain Guides

Fig 12: Inspecting Secondary Timing Chain Guide
Courtesy of GENERAL MOTORS CORP.
1. Inspect the secondary timing chain guides for the following:
   • Worn guide surface (1)
   • Cracked or broken guide surface (2)
   • Cracked or damaged guide base (3)
2. Replace a damaged secondary timing chain guide.

Secondary Timing Chain Shoes

Fig 13: Inspecting Secondary Timing Chain Shoes
Courtesy of GENERAL MOTORS CORP.
1. Inspect the secondary timing chain shoes for the following:
   • Worn shoe surface (1)
   • Cracked or broken shoe surface (2)
   • Cracked or damaged shoe (3)
2. Replace a damaged secondary timing chain shoe.

Primary Timing Chain Tensioner

Fig 14: Inspecting Primary Timing Chain Tensioner
Courtesy of GENERAL MOTORS CORP.
1. Inspect the primary timing chain tensioner for worn primary timing chain tensioner shoe surface (1).
2. Inspect the primary timing chain tensioner for locked or binding timing chain tensioner. Release the locking lever (2) and ensure the plunger moves freely (3) in and out of the body of the tensioner.
3. Replace a damaged primary timing chain tensioner.

Secondary Timing Chain Tensioners

Fig 15: Inspecting Secondary Timing Chain Tensioner
Courtesy of GENERAL MOTORS CORP.
1. Inspect the secondary timing chain tensioner for damaged plunger-to-shoe contact surface (1).
2. Inspect the secondary timing chain tensioner for locked or binding timing chain tensioner. Release the locking lever (2) and ensure the plunger moves freely (3) in and out of the body of the tensioner.
3. Replace a damaged primary and/or secondary timing chain tensioner.

Timing Component Fasteners

1. Inspect the timing component fasteners.
2. Replace any damaged timing component fasteners, do not repair.