GM Full Size Vans 1987-1997 Repair Guide

Crankshaft Damper

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REMOVAL & INSTALLATION



See Figures 1 through 7

A torsional damper puller tool is required to perform this procedure.

  1. Disconnect the negative battery cable.
  2.  
  3. Remove the fan shroud assembly.
  4.  
  5. Remove the cooling fan belts, fan and pulley.
  6.  
  7. If necessary, remove the radiator.
  8.  



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Fig. Fig. 1: On some models you will have to remove the damper hub-to-crankshaft bolt before the pulley



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Fig. Fig. 2: The hub bolt on this engine has a large flat washer which spreads the clamp load on the pulley



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Fig. Fig. 3: Loosen and remove the retaining bolts around the perimeter of the pulley face ...

  1. Remove the accessory drive pulley (crankshaft pulley on diesel engines).
  2.  
  3. Remove the torsional damper bolt.
  4.  
  5. Remove the torsional damper using a suitable puller.
  6.  

Make sure you do not lose the crankshaft key, if it has been removed.



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Fig. Fig. 4: ... then remove the pulley from the damper



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Fig. Fig. 5: Use a suitable (non-jawed) puller to loosen the damper on the crankshaft



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Fig. Fig. 6: Once loosened, the damper is easily removed:

To install:
  1. Coat the crankshaft stub with engine oil.
  2.  
  3. Position the crankshaft key if one was used. If you pulled the crank seal, replace it with the open end facing in.
  4.  

The inertial weight section of the damper is attached to the hub with a rubber-like material. The correct installation procedures, with the proper tools, MUST be followed or the resultant movement of the inertial weight will destroy the tuning of the damper!

  1. Thread the stud on the tool into the end of the crankshaft.
  2.  
  3. Position the damper on the shaft and tap it into place with a plastic mallet (lightly!). Make sure the key is in place by securing it with a little RTV sealant.
  4.  
  5. Install the bearing, washer and nut and then turn the nut until the damper is pulled into position. Remove the tool.
  6.  



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Fig. Fig. 7: If necessary, drive a new oil seal into place before reinstalling the damper:

  1. Make sure the damper is all the way on, then install the bolt. Tighten the bolt as follows:

    1987-95 models: 4.3L, 5.0L & 5.7L engines: 70 ft. lbs. (95 Nm)
     
    1996-97 models: 4.3L, 5.0L & 5.7L engines: 74 ft. lbs. (100 Nm)
     
    6.2L & 6.5L engine: 200 ft. lbs. (270 Nm)
     
    1987-95 models: 7.4L engine: 85 ft. lbs. (115 Nm)
     
    1996-97 models: 7.4L engine: 110 ft. lbs. (149 Nm)
     

  2.  

  1. Install the remaining components and road test the van.
  2.  

 
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