Installation Procedure

Important:  Make sure the darkened chain links on the left secondary camshaft drive chain are facing inward.

1. Position the left secondary camshaft drive chain to the left intake camshaft sprocket.
2. Place the left intake camshaft (1) in position in the cylinder head.
3. Position the camshaft lobes in a neutral position with the front notch for the camshaft sprocket drive pins near the top of their rotation and the flats machined into the camshaft parallel and facing the cylinder head.
   Fig 1: Installing Left Intake Camshaft

   Courtesy of GENERAL MOTORS CORP.
4. Observe the markings on the bearing caps. Each bearing cap is marked in order to identify its location. The markings have the following meanings:
   • The raised feature must always be oriented toward the outboard side of the engine.
   • The "I" indicates the intake camshaft.
   • The "E" indicates the exhaust camshaft.
   • The number indicates the journal position from the front of the engine.
5. Apply a liberal amount of lubricant GM P/N 12345501 or equivalent to the camshaft bearing caps.
   Fig 2: Identifying Markings On Bearing Caps

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6. Install the camshaft bearing cap bolts according to the identification marks.
   CAUTION: Refer to FASTENER NOTICE in Cautions and Notices.
7. Tighten the camshaft bearing caps.

   Tighten 

   1. 7.1. Alternately hand tighten the camshaft bearing cap bolts a few turns at a time until all caps are fully seated.
   2. 7.2. Tighten the camshaft bearing cap bolts to 8 N.m (71 lb in).
   3. 7.3. Tighten the camshaft bearing cap bolts an additional 22 degrees using the J 36660-A. 
   Fig 3: Installing Camshaft Bearing Caps

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   WARNING: 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

   Important:  There should be no need to rotate the camshaft more then 10 degrees.

8. Using the hex cast into the camshaft, rotate the camshaft so the rear camshaft flat is facing the cylinder head in order to install the J 42038 
9. Install the J 42038  to the rear of the camshafts on the left cylinder head.
   Fig 4: Installing J 42038

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10. Slide the intake camshaft sprocket off of the J 42042  and onto the camshaft, aligning the drive pin into the camshaft notch.
11. Remove the J 42042  from the left cylinder head.
    Fig 5: Locating J 42042

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12. Tighten the primary camshaft drive chain guide upper bolts.

    Tighten 

    Tighten the primary camshaft drive chain guide bolts to 25 N.m (18 lb ft).

    Important:  Ensure that each chain guide access plug has an O-ring installed.

13. Install the 2 chain guide access plugs (3, 4).

    Tighten 

    Tighten the chain guide access plugs to 5 N.m (44 lb in).

    Fig 6: Installing Chain Guide Access Plugs

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14. Install the intake camshaft sprocket bolt.

    Tighten 

    1. 14.1. Tighten the camshaft sprocket bolt to 25 N.m (18 lb ft).
    2. 14.2. Use the J 36660-A  in order to tighten the camshaft sprocket bolt an additional 45 degrees.
15. Install the left secondary camshaft drive chain tensioner. Refer to Secondary Camshaft Drive Chain Tensioner Replacement - Left .
    Fig 7: Installing Intake Camshaft Sprocket Bolt

    Courtesy of GENERAL MOTORS CORP.