How to Replace Timing Chain on Buick LaCrosse?

The details to replace Timing Chain & Sprockets are as follows.

The procedure is mentioned for both the engine models.
3.6L & 3.8L.


Timing Chain & Sprockets
REMOVAL & INSTALLATION details  and Diagrams are mentioned below:---

3.6L Engine

1. Before servicing the vehicle, refer to the Precautions Section.
2. Remove the timing chain cover and seal. Refer to Timing Chain Cover and Seal, removal and installation. 
   
   
   
   Fig. The right bank secondary camshaft drive chain tensioner-3.6L Engine
3. Remove the right bank secondary camshaft drive chain tensioner:
   1. Remove the right secondary camshaft drive chain tensioner bolts.
   2. Remove the right secondary camshaft drive chain tensioner.
   3. Remove and discard the right secondary camshaft drive chain tensioner gasket.
   4. Inspect the right secondary camshaft drive chain tensioner mounting surface on the right cylinder head for burrs or any defects that would degrade the sealing of the NEW right secondary camshaft drive chain tensioner gasket. 
      
      
      
      Fig. The right secondary camshaft drive chain shoe bolt and drive chain shoe-3.6L Engine
4. Remove the right bank secondary camshaft drive chain shoe:
   1. Remove the right secondary camshaft drive chain shoe bolt.
   2. Remove the right secondary camshaft drive chain shoe. 
      
      
      
      Fig. The right bank secondary camshaft drive chain guide-3.6L Engine
5. Remove the right bank secondary camshaft drive chain guide:
   1. Remove the right secondary camshaft drive chain guide bolts.
   2. Remove the right secondary camshaft drive chain guide.
      
      
      

      

      Fig. The right bank secondary camshaft drive chain-3.6L Engine
6. Remove the right secondary camshaft drive chain from the right camshaft position actuators and the right camshaft intermediate drive chain idler sprocket.
   
   
   

   

   Fig. The primary camshaft drive chain tensioner-3.6L Engine
7. Remove the primary camshaft drive chain tensioner:
   1. Remove the primary camshaft drive chain tensioner bolts.
   2. Remove the primary camshaft drive chain tensioner.
   3. Remove and discard the primary camshaft drive chain tensioner gasket.
   4. Inspect the primary camshaft drive chain tensioner mounting surface on the engine block for burrs or any defects that would degrade the sealing of the NEW primary camshaft drive chain tensioner gasket.
      
      
      

      

      Fig. The primary camshaft drive chain upper guide-3.6L Engine
8. Remove the primary camshaft drive chain upper guide:
   1. Remove the primary camshaft drive chain upper guide bolts.
   2. Remove the primary camshaft drive chain upper guides.

To install:

NOTE

Ensure that the crankshaft is in the stage one timing drive assembly position.

1. Install the primary camshaft drive chain:
   1. Wrap the primary camshaft drive chain around the large sprockets of each camshaft intermediate drive chain idler and the crankshaft sprocket.
      
      
      

      

      Fig. Line up the left camshaft intermediate drive chain idler timing mark and the timing camshaft drive chain link-3.6L Engine
   2. The left camshaft intermediate drive chain idler timing mark (1) will align with a timing camshaft drive chain link (2).
      
      
      

      

      Fig. Line up the right camshaft intermediate drive chain idler timing mark and the timing camshaft drive chain link-3.6L Engine
   3. The right camshaft intermediate drive chain idler timing mark (2) will align with a timing camshaft drive chain link (1).
      
      
      

      

      Fig. The crankshaft sprocket timing mark will align with a timing camshaft drive chain link-3.6L Engine
   4. The crankshaft sprocket timing mark (2) will align with the timing camshaft drive chain link (1).
      
      
      

      

      Fig. Ensure all the timing marks are properly aligned with the timing camshaft drive chain links-3.6L Engine
   5. Ensure all the timing marks (2, 3, 6) are properly aligned with the timing camshaft drive chain links (1, 4, 5).
      
      
      

      

      Fig. The primary camshaft drive chain upper guide-3.6L Engine
2. Install the primary upper camshaft drive chain guide.
3. Install the upper primary camshaft drive chain guide bolts. Tighten bolts to 17 ft. lbs. (23 Nm).
4. Using the J 45027, reset the primary camshaft drive chain tensioner plunger.
5. Install the plunger into the primary camshaft drive chain tensioner body.
6. Compress the plunger into the body and lock the primary camshaft drive chain tensioner by inserting the EN 46112 into the access hole in the side of the primary camshaft drive chain tensioner body.
7. Slowly release pressure on the primary camshaft drive chain tensioner. The primary camshaft drive chain tensioner should remain compressed.
8. Install a NEW primary camshaft drive chain tensioner gasket to the primary camshaft drive chain tensioner.
9. Install the primary camshaft drive chain tensioner bolts through the primary camshaft drive chain tensioner and gasket.
   
   
   

   

   Fig. The primary camshaft drive chain tensioner-3.6L Engine
10. Place the primary camshaft drive chain tensioner into position and loosely install the bolts to the block.
11. Tighten the primary camshaft drive chain tensioner bolts:
    1. Step 1: 44 inch lbs. (5 Nm).
    2. Step 2: 17 ft. lbs. (23 Nm).
12. Release the primary camshaft drive chain tensioner by pulling out the EN 46112 and unlocking the tensioner plunger.
    
    
    

    

    Fig. Verify the primary and left secondary camshaft drive chain timing mark alignments-3.6L Engine
13. Verify the primary and left secondary camshaft drive chain timing mark alignments (1-12).
    
    
    

    

    Fig. Remove the EN 46105-1 from the rear of the left camshafts-3.6L Engine
14. Remove the EN 46105-1 from the rear of the left camshafts.
    
    
    

    

    Fig. Using the EN 46111, rotate the crankshaft and crankshaft sprocket from the stage 1 alignment position (1) to the stage 2 alignment position (2)-3.6L Engine
15. Using the EN 46111, rotate the crankshaft and crankshaft sprocket from the stage 1 alignment position (1) to the stage 2 alignment position (2), 115 crankshaft degrees, in order to install the right secondary camshaft drive chain components.
    
    
    

    

    Fig. Install the EN 46105-2 onto the rear of the left camshafts-3.6L Engine
16. Install the EN 46105-2 onto the rear of the left camshafts.
    
    
    

    

    Fig. Install the EN 46105-1 onto the rear of the right camshafts-3.6L Engine
17. Install the EN 46105-1 onto the rear of the right camshafts.
    
    
    

    

    Fig. Ensure that the crankshaft is in the stage 2 timing drive assembly position (2)-3.6L Engine
18. Ensure that the crankshaft is in the stage 2 timing drive assembly position (2).
    
    
    

    

    Fig. The right bank secondary camshaft drive chain-3.6L Engine
19. Install the right secondary camshaft drive chain.
    
    
    

    

    Fig. Place the secondary camshaft drive chain around the right camshaft intermediate drive chain idler outer sprocket, aligning the timing camshaft drive chain link (1) with the alignment access hole (2) made in the right camshaft intermediate drive chain idler inner sprocket-3.6L Engine
20. Place the secondary camshaft drive chain around the right camshaft intermediate drive chain idler outer sprocket, aligning the timing camshaft drive chain link (1) with the alignment access hole (2) made in the right camshaft intermediate drive chain idler inner sprocket.
    
    
    

    

    Fig. Ensure there are 10 links (1) between the timing camshaft drive chain links for the camshaft position actuator sprockets-3.6L Engine
21. Wrap the secondary camshaft drive chain around both right actuator drive sprockets.
22. Ensure there are 10 links (1) between the timing camshaft drive chain links for the camshaft position actuator sprockets.
23. Align the right exhaust camshaft position actuator sprocket alignment triangle mark with the timing camshaft drive chain link.
24. Align the right intake camshaft position actuator sprocket alignment triangle mark with the timing camshaft drive chain link.
    
    
    

    

    Fig. There will be 22 links (1) between the right camshaft intermediate drive chain idler timing camshaft drive chain link and each right camshaft position actuator sprocket timing camshaft drive chain link-3.6L Engine
25. Ensure that there are 22 links (1) between the right camshaft intermediate drive chain idler timing camshaft drive chain link and each right camshaft position actuator sprocket timing camshaft drive chain link.
    
    
    

    

    Fig. The right bank secondary camshaft drive chain guide-3.6L Engine
26. Position the right secondary camshaft drive chain guide.
27. Install the secondary camshaft drive chain guide bolts. Tighten the bolts to 17 ft. lbs. (23 Nm).
    
    
    

    

    Fig. The right secondary camshaft drive chain shoe bolt and drive chain shoe-3.6L Engine
28. Position the right secondary camshaft drive chain shoe.
29. Install the secondary camshaft drive chain shoe bolt. Tighten the bolt to 17 ft. lbs. (23 Nm).
30. Using the J 45027, reset the right secondary camshaft drive chain tensioner plunger.
31. Install the plunger into the right secondary camshaft drive chain tensioner body.
32. Compress the plunger into the body and lock the right secondary camshaft drive chain tensioner by inserting the EN 46112 into the access hole in the side of the right secondary camshaft drive chain tensioner body.
33. Slowly release pressure on the right secondary camshaft drive chain tensioner.
    
    NOTE

    The right secondary camshaft drive chain tensioner should remain compressed.
34. Install a NEW right secondary camshaft drive chain tensioner gasket to the right secondary camshaft drive chain tensioner.
35. Install the right secondary camshaft drive chain tensioner bolts through the right secondary camshaft drive chain tensioner and gasket.
    
    NOTE

    Ensure the right secondary camshaft drive chain tensioner mounting surface on the right cylinder head does not have any burrs or defects that would degrade the sealing of the NEW right secondary camshaft drive chain tensioner gasket.
    
    
    
    
    

    

    Fig. The right bank secondary camshaft drive chain tensioner-3.6L Engine
36. Place the right secondary camshaft drive chain tensioner into position and loosely install the bolts to the block.
37. Verify the proper placement of the right secondary camshaft drive chain tensioner gasket tab.
38. Tighten the right secondary camshaft drive chain tensioner bolts:
    1. Step 1: 44 inch lbs. (5 Nm).
    2. Step 2: 17 ft. lbs. (23 Nm).
39. Release the right camshaft drive chain tensioner by pulling out the EN 46112 and unlocking the tensioner plunger.
    
    WARNING

    Ensure that all timing chain tensioners are completely released. A timing chain tensioner that is not properly released can lead to serious engine damage.
    
    
    
    
    

    

    Fig. Verify all primary and secondary camshaft drive chain timing mark alignments-3.6L Engine
40. Verify all primary and secondary camshaft drive chain timing mark alignments (1-18).
41. Install the timing chain cover and seal. Refer to Timing Chain Cover and Seal, removal and installation.

3.8L Engine

Fig. Timing chain front cover-3.8L engines

1. Before servicing the vehicle, refer to the Precautions Section.
2. Drain the cooling system.
3. Support the engine.
4. Remove or disconnect the following:
   
   
   Negative battery cable

   Torque axis mount and bracket

   Drive belt

   Drive belt tensioner

   Crankshaft damper

   Crankshaft Position (CKP) sensor shield and the CKP sensor

   Oil pan to front cover bolts

   Timing chain front cover
5. Align the timing marks on the camshaft and crankshaft sprockets so they are as close together as possible.
   
   WARNING

   Do not rotate the camshaft or crankshaft while the timing chain and sprockets are removed.
   
   
   
   
   Timing chain damper

   Camshaft sprocket bolt, the camshaft sprocket and timing chain

   Crankshaft sprocket

To install:

1. Install or connect the following:
   
   WARNING

   The oil pump is built into the front cover. When the cover is removed, oil drains from the pump. Since the pump "loses its prime" it may not establish oil pressure as soon as the engine starts. Therefore, it is important to remove the oil pump cover from the back of the timing chain front cover and pack the space around the oil pump gears completely full of petroleum jelly. If this is not done, the oil pump may not pump engine oil when the engine is started, resulting in severe engine damage.
   
   
   
   
   Timing chain and sprockets with the timing marks aligned

   Camshaft sprocket bolt. Torque the bolt to 74 ft. lbs. (100 Nm) plus an additional 90° turn.
   
   
   
   
   Timing chain damper. Torque the bolts to 16 ft. lbs. (22 Nm).
2. Remove the screws and the oil pump cover from the back of the timing chain front cover. Pack the space around the oil pump gears completely full of petroleum jelly. There must be no air space left inside the pump.
3. Install or connect the following:
   
   
   Pump cover with new gaskets. Torque the screws to 97 inch lbs. (11 Nm).

   Timing chain front cover. Torque the front cover to engine bolts to 11 ft. lbs. (15 Nm) plus an additional 40°.

   Oil pan to front cover bolts. Torque the bolts to 125 inch lbs. (14 Nm).

   CKP sensor. Torque the bolts to 14-28 ft. lbs. (20-40 Nm).

   CKP sensor shield

   Crankshaft damper. Torque the bolt to 111 ft. lbs. (150 Nm) plus an additional 76° turn.

   Drive belt tensioner assembly

   Right inner fender access panel and the right front wheel

   Drive belt(s)

   Engine mount

   Coolant hoses

   Negative battery cable
4. Remove the engine support fixture.
5. Refill and bleed the cooling system.
6. Start the vehicle and check for leaks and proper engine operation.
   
   
   

   

   Fig. Timing chain sprocket and balance shaft gear alignment-3.8L engines

These details will help.

Thanks.

FOR MORE HELP GO TO: ---

Car repair guide?

http://technoanswers.blogspot.in/2012/03/car-repair-guide.html