Primary Camshaft Intermediate Drive Chain Installation

Special Tools 

J 39946:  Crankshaft Socket - 4.0L and 4.6L

For equivalent regional tools, refer to Special Tools .

Fig 1: Aligning Timing Marks Of Camshaft Intermediate & Crankshaft Sprockets
Courtesy of GENERAL MOTORS CORP.
1. Install the primary camshaft drive chain on the camshaft intermediate drive shaft sprocket and crankshaft sprocket.
2. Align the timing marks (1) of the camshaft intermediate drive shaft sprocket and crankshaft sprocket. Ensure the marks are aligned vertically.
Fig 2: Primary Camshaft Drive Chain, Intermediate Drive Shaft Sprocket & Crankshaft Sprocket
Courtesy of GENERAL MOTORS CORP.
3. Ensure the number one piston is at Top Dead Center (TDC) and the crankshaft pin (1) is approximately at the one o'clock position using the J 39946:  socket.
4. Install the primary camshaft drive chain, camshaft intermediate drive shaft sprocket and crankshaft sprocket as an assembly (3) onto the camshaft intermediate drive shaft (4) and the crankshaft (2).
Fig 3: Camshaft Intermediate Sprocket Retaining Bolt
Courtesy of GENERAL MOTORS CORP.
CAUTION: Refer to Fastener Caution .
5. Install the camshaft intermediate drive shaft sprocket bolt and tighten to 60 N.m (44 lb ft).
Fig 4: Primary Camshaft Drive Chain Guide & Bolts
Courtesy of GENERAL MOTORS CORP.
6. Install the primary camshaft drive chain guide.
7. Install the primary camshaft drive chain guide bolts and tighten to 25 N.m (18 lb ft).
Fig 5: Collapsing Camshaft Drive Chain Tensioner
Courtesy of GENERAL MOTORS CORP.
8. Collapse the primary camshaft drive chain tensioner using the following procedure:
   1. Rotate the ratchet release lever counterclockwise and hold.
   2. Collapse the primary camshaft drive chain tensioner shoe and hold.
   3. Release the ratchet lever and slowly release the pressure on the shoe.
9. When the ratchet lever moves to the first detent a click should be heard and felt. Insert a pin through the hole in the release lever in order to lock the primary camshaft drive chain tensioner shoe in the collapsed position.
Fig 6: Primary Camshaft Drive Chain Tensioner & Bolts
Courtesy of GENERAL MOTORS CORP.
NOTE: Ensure the primary camshaft drive chain tensioner release lever is facing out.
10. Install the primary camshaft drive chain tensioner.
11. Install the primary camshaft drive chain tensioner bolts and tighten to 25 N.m (18 lb ft).
12. Remove the pin in the release lever locking the primary camshaft drive chain tensioner.
Fig 7: Timing Mark Vertical Alignment
Courtesy of GENERAL MOTORS CORP.
13. Ensure the timing marks (1) are aligned vertically.