S&T Series Blazer, Bravada, Envoy, Jimmy, Rainier, Trailblazer, Xtreme

Crankshaft Damper (Balancer)

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Removal & Installation



4.2L Engine
  1. Remove the cooling fan and shroud, as outlined in this section.
  2.  
  3. Remove the drive belt.
  4.  
  5. Carefully loosen and remove the balancer bolt.
  6.  
  7. Install Crankshaft End Protector, special tool no. J 41816-2, into the end of the crankshaft.
    WARNING
    Do not pull on outer edge of the crankshaft balancer.

  8.  
  9. Use a 3 jaw puller to remove the crankshaft balancer.

    Click image to see an enlarged view

    Fig. Install Crankshaft End Protector, special tool no. J 41816-2, into the end of the crankshaft, then use a 3 jaw puller to remove the crankshaft balancer

  10.  
  11. Remove the 3 jaw puller and the Crankshaft End Protector .
  12.  
  13. Remove the crankshaft balancer shim from the crankshaft snout.
  14.  
  15. Clean and inspect the crankshaft balancer.
  16.  

To install:


WARNING
The crankshaft balancer does not have a key-way; so the crankshaft could turn when tightening, causing an improper torque. Make sure to follow the installation procedure to prevent damage.

  1. Raise the vehicle.
  2.  
  3. Remove the torque converter access plug in the dry part of the oil pan.
  4.  
  5. Use the torque converter holding tool from the Crankshaft Balancer Remover/Holder Kit, special tool no. J 44226, and secure the torque converter while tightening the crankshaft balancer.
  6.  
  7. Install a new crankshaft balancer shim GM P/N 12573950 over the crankshaft snout, against the crankshaft gear.
  8.  
  9. Using the Crankshaft Front Oil Seal Installer, special tool no. J 41478, install and seat the crankshaft balancer.
  10.  
  11. Remove the Crankshaft Front Oil Seal Installer.
  12.  
  13. While still holding the flywheel, install the balancer washer and the bolt. Tighten the crankshaft balancer bolt to 110 ft. lbs. (150 Nm). Use a torque angle meter to tighten the balancer bolt an additional 180 degrees.
  14.  
  15. Remove the torque converter holding tool.
  16.  
  17. Install the torque converter access plug into the oil pan.
  18.  
  19. Lower the vehicle.
  20.  
  21. Install the drive belt.
  22.  
  23. Install the cooling fan and shroud.
  24.  

4.3L Engines

Most of the 4.3L engines are equipped with a crankshaft hub and pulley assembly. The pulley is usually mounted to the hub using 3 or so bolts around the inner circle of the pulley. The center mounting bolt is used to retain the hub to the crankshaft, but may also be used to retain the pulley. If the center mounting bolt also retains the pulley, a washer can normally be seen between the bolt head and the inner lip of the pulley.

  1. Disconnect the negative battery cable.
  2.  
  3. Loosen and remove the accessory drive belts or serpentine drive belt from the crankshaft damper.
  4.  
  5. If necessary for access on certain models, remove the fan assembly.
  6.  
  7. Remove the pulley mounting bolts from the pulley and damper assembly. If the center mounting bolt is not used to retain the pulley, it may be separated from the hub at this time and removed from the engine.
  8.  
  9. Spray the damper bolt with penetrating oil and allow it to soak in for at least a few minutes. Loosen and remove the center crankshaft damper bolt. If the pulley was not removed earlier, it should be free now.
    NOTE
    If damper bolt removal is difficult, various methods may be used to hold the crankshaft while loosening or tightening the bolt. One method involves installing a flywheel holding fixture to prevent the crankshaft from turning. A holding tool may be available for some dampers which threads into the pulley bolt holes. But most importantly of all, allow the penetrating oil to do the work when loosening an old damper bolt and reapply oil, as necessary. If you have the time, you might even want the oil to sit overnight.

  10.  
  11. Remove the damper from the end of the crankshaft using a suitable threaded damper puller, NOT a jawed-type puller which would most likely destroy dampers with bonded hubs.
    WARNING
    The use of any other type of puller, such as a universal claw type which pulls on the outside of the hub, can destroy the balancer on some of these engines. Many of the vehicles covered in this manual use a balancer, the outside ring of which is bonded in rubber to the hub. Pulling on the outside will break the bond.



    Click image to see an enlarged view

    Fig. Unfasten the pulley mounting bolts-4.3L engine



    Click image to see an enlarged view

    Fig. Unfasten the center pulley bolts and remove the pulley from the vehicle-4.3L engine



    Click image to see an enlarged view

    Fig. Using a suitable puller, disengage the damper from the crankshaft-4.3L engine



    Click image to see an enlarged view

    Fig. Remove the damper from the vehicle-4.3L engine

  12.  

To install:

  1. If removal of the damper was difficult, check the damper inner diameter and the crankshaft outer diameter for corrosion. A small amount of corrosion may be removed using steel wool, then the surface may be lubricated lightly using clean engine oil.
  2.  
  3. Coat the front cover seal contact edge of the damper lightly with clean engine oil, then apply a small amount of RTV sealant to the keyway in the damper hub. Install the damper on the end of the crankshaft (along with the pulley if the share the center retaining bolt), but DO NOT hammer it into position, instead use a damper installation tool to slowly draw the hub into position. If the damper can be positioned far enough over the end of the crankshaft, the damper bolt may be used to draw it into position, but be careful that sufficient threads are in contact to prevent stripping the bolt or crankshaft.
  4.  
  5. Once the damper is fully seated, install and tighten the retaining bolt to 74 ft. lbs. (100 Nm).
  6.  
  7. If not done earlier, install the pulley and secure using the outer retaining bolts. tighten the pulley bolts to 43 ft. lbs. (58 Nm).
  8.  
  9. If removed for access, install the fan assembly.
  10.  
  11. Install the drive belt(s) to the crankshaft pulley.
  12.  
  13. Connect the negative battery cable.
  14.  

5.3L Engine

This procedure requires the use of the following special tools, or their equivalents:



J 41816 Crankshaft Balancer Remover
 
J 41816-2 Crankshaft End Protector
 
J 42386-A Flywheel Holding Tool
 
J 41665 Crankshaft Balancer and Sprocket Installer
 
J 36660-A Torque Angle Meter
 

  1. Remove the accessory drive belt, as outlined in this section.
  2.  
  3. Remove the air conditioning (A/C) drive belt, if equipped, as outlined in this section.
  4.  
  5. Remove the fan shroud.
  6.  
  7. Remove the starter motor.
    NOTE
    Make sure the teeth of J 42386-A mesh with the teeth of the engine flywheel. The crankshaft balancer is balanced as an individual component. It is not necessary to mark the balancer prior to removal

  8.  
  9. Install J 42386-A Flywheel Holding Tool and bolts. Use one M10-1.5 x 120 mm and one M10-1.5 x 45 mm bolt for proper tool operation. Tighten the tool bolts to 37 ft. lbs. (50 Nm).

    Click image to see an enlarged view

    Fig. Install J 42386-A Flywheel Holding Tool and bolts. Use one M10-1.5 x 120 mm and one M10-1.5 x 45 mm bolt for proper tool operation. Tighten the tool bolts to 37 ft. lbs. (50 Nm)

  10.  
  11. Remove the crankshaft balancer bolt. Do not discard the crankshaft balancer bolt. The balancer bolt will be used during the balancer installation procedure.
  12.  
  13. Use J 41816 Crankshaft Balancer Remover and J 41816-2 Crankshaft End Protector tools in order to remove the crankshaft balancer.

    Click image to see an enlarged view

    Fig. Use J 41816 Crankshaft Balancer Remover and J 41816-2 Crankshaft End Protector tools in order to remove the crankshaft balancer

  14.  
  15. Remove to tools from the crankshaft balancer.
  16.  
  17. Clean and inspect the crankshaft balancer.
  18.  

To install:


NOTE
Ensure that the teeth of the Flywheel Holding Tool J 42386-A mesh with the teeth of the engine flywheel. The used crankshaft balancer bolt will be used only during the first pass of the balancer installation procedure. Install a NEW bolt and tighten as described in the second pass of the balancer bolt tightening procedure. The crankshaft balancer installation and bolt tightening involves a four stage tightening process. The first pass ensures that the balancer is installed completely onto the crankshaft. The second, third, and forth passes tighten the new bolt to the proper torque.


NOTE
Position the balancer onto the end of the crankshaft as straight as possible prior to tool installation.

  1. Install the crankshaft balancer onto the end of the crankshaft.
  2.  
  3. Use J 41665 Crankshaft Balancer and Sprocket Installer tool in order to install the crankshaft balancer.

    Click image to see an enlarged view

    Fig. Use J 41665 Crankshaft Balancer and Sprocket Installer tool in order to install the crankshaft balancer

  4.  
  5. Assemble the threaded rod, nut, washer and installer. Insert the smaller end of the installer into the front of the balancer.
  6.  
  7. Use a wrench and hold the hex end of the threaded rod.
  8.  
  9. Use a second wrench and rotate the installation tool nut clockwise until the balancer is started onto the crankshaft.
  10.  
  11. Remove the tool and reverse the installation tool. Position the larger end of the installer against the front of the balancer.
  12.  
  13. Use a wrench and hold the hex end of the threaded rod.
  14.  
  15. Use a second wrench and rotate the installation tool nut clockwise until the balancer is installed onto the crankshaft.
  16.  
  17. Remove the balancer installation tool.
  18.  
  19. Install the used crankshaft balancer bolt. Tighten the USED bolt to 240 ft. lbs. (330 Nm).
  20.  
  21. Remove the used crankshaft balancer bolt.
    NOTE
    Recess the nose of the crankshaft 0.094-0.176 in (2.4-4.48 mm) into the balancer bore.



    Click image to see an enlarged view

    Fig. Recess the nose of the crankshaft 0.094-0.176 in (2.4-4.48 mm) into the balancer bore

  22.  
  23. Measure for a correctly installed balancer. If the balancer is not installed to the proper dimensions, install the Crankshaft Balancer and Sprocket Installer tool and repeat the installation procedure.
  24.  
  25. Install a NEW crankshaft balancer bolt. Tighten the bolt as follows:
    1. First pass: 37 ft. lbs. (50 Nm).
    2.  
    3. Final pass to 140 degrees using Torque Angle Meter J 36660-A or equivalent.
    4.  

  26.  
  27. Remove the flywheel holding tool and bolts.
  28.  
  29. Install the starter motor.
  30.  
  31. Install the fan shroud.
  32.  
  33. Install the A/C drive belt, if equipped.
  34.  
  35. Install the accessory drive belt.
  36.  
  37. Use an OBD-II compliant scan tool to perform the Crankshaft Position (CKP) system variation learn procedure.
  38.  

 
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