Tools Required

1. Remove the right camshaft cover. Refer to Camshaft Cover Replacement - Right Side .
2. Remove the camshaft position (CMP) sensor. Refer to Camshaft Position Sensor Replacement in Engine Controls - 4.6L.



3. Rotate the crankshaft to top dead center (TDC) of the # 1 cylinders compression stroke, both camshaft sprocket drive pins should be at the top of their rotation.




Caution: The camshaft holding tools must be installed on the camshafts to prevent camshaft rotation. When performing service to the valve train and/or timing components, valve spring pressure can cause the camshafts to rotate unexpectedly and can cause personal injury.

4. Install the J 44212 over the camshafts.



5. Use a paint stick to create a mark (1) on the timing chain link adjacent to each camshaft sprocket timing mark (2, 3).



6. Install the (1) using the procedure below:



7. Rotate the wing nut (3) of the to the top of its travel.



8. Position the bottom retention tool on the cylinder head with the V-notch of the block (1) adjacent to the right exhaust camshaft sprocket and chain.



9. Insert the hook end (2) into a secondary timing chain link as shown.



10. Rotate the wing nut until it contacts the retention tool block. DO NOT tighten the wing nut at this time.



11. Rotate the wing nut of the (4) to the top of its travel.



12. Position the top retention tool on the cylinder head with the V-notch of the block (1) adjacent to the right intake camshaft sprocket and chain.



13. Insert the hook end (2) into a secondary timing chain link as shown.



14. Rotate the wing nut until it contacts the retention tool block (1). Alternately tighten both wing nuts to retain the chain.



15. Use an open wrench on the hex cast into the camshafts in order to prevent the camshafts from rotating when removing the camshaft sprocket bolts.



16. Remove the camshaft sprocket bolts.



17. Alternately loosen the camshaft bearing cap bolts a few turns at a time until all valve spring pressure has been released.
18. Remove the camshaft bearing caps.
19. Remove the J 44212 from the camshafts.



20. Remove the camshafts.



21. Remove the camshaft followers.
22. Clean and inspect the camshafts. Refer to Camshaft Cleaning and Inspection .

1. Apply a liberal amount of lubricant GM P/N 12345001 or equivalent to the roller pivot pocket (2) and valve slot areas (1) of the camshaft followers.




Important: The follower must be positioned squarely on the valve tip so that the full width of the roller will completely contact the camshaft lobe. If the followers are being reused you must put them back in their original location.

2. Place the camshaft followers in position on the valve tip and the stationary hydraulic lash adjusters (SHLA) (1). The rounded head of the follower goes on the SHLA, while the flat end goes on the valve tip.
3. Clean the camshaft carriers with a clean, lint-free cloth.



4. Apply a liberal amount of lubricant GM P/N 12345001 or equivalent to the camshaft carriers, camshaft lobes (1) and the camshaft journals (2).
5. Place the camshaft in the camshaft carriers with the camshaft sprocket drive pins near the top of their rotation and the camshaft lobes in a neutral position. The camshafts can be identified by a stamping near the rear journal. For example: R-EXH is defined as right bank exhaust.



6. Observe the markings on the camshaft bearing caps. Each camshaft bearing cap is marked in order to identify its location. The markings have the following meanings:

•	The arrow should point to the front of the engine.

•	The number indicates the position from the front of the engine.

•	The "E" indicates the exhaust camshaft.

•	The "I" indicates the intake camshaft.

7. Apply a liberal amount of lubricant GM P/N 12345001 or equivalent to the camshaft bearing caps.



8. Install the camshaft bearing caps according to the identification marks.

Notice: Refer to Fastener Notice in the Preface section.




9. Install the camshaft bearing cap bolts in sequence.

Tighten

1. Alternately hand tighten the camshaft bearing cap bolts a few turns at a time until all caps are fully seated.
2. Tighten the camshaft bearing cap bolts to 5 N·m (44 lb in).
3. Tighten the camshaft bearing cap bolts an additional 30 degrees using the J 45059 .
10. Align the camshafts.




Caution: The camshaft holding tools must be installed on the camshafts to prevent camshaft rotation. When performing service to the valve train and/or timing components, valve spring pressure can cause the camshafts to rotate unexpectedly and can cause personal injury.

11. Install the J 44212 over the camshafts.

Important: Ensure the camshaft sprockets properly engage the camshaft sprocket drive pins and camshafts.

12. Slide the intake and exhaust camshaft sprockets off the pins of the J 44213 and onto the pins of the camshafts.



13. Use an open wrench on the hex cast into the camshafts in order to prevent the camshafts from rotating when tightening the camshaft sprocket bolts.



14. Install the camshaft sprocket bolts.

Tighten
Tighten the camshaft sprocket bolts to 120 N·m (89 lb ft).




15. Verify the camshaft sprocket alignment.



16. Remove the J 44212 from the camshafts.
17. Install the CMP sensor. Refer to Camshaft Position Sensor Replacement in Engine Controls - 4.6L.
18. Install the right camshaft cover. Refer to Camshaft Cover Replacement - Right Side .