GM Full-Size Trucks 1988-1998 Repair Information

Front or Rear Output Shaft Seal

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REMOVAL & INSTALLATION



See Figures 1, 2 and 3

  1. Raise and support the truck on jackstands.
  2.  
  3. Remove the skid plate if necessary to gain access to the front seal.
  4.  
  5. Matchmark and remove the driveshaft.
  6.  
  7. Remove the nut, washer and yoke.
  8.  

Some models don't use a washer at the rear yoke nut.

  1. Some models employ a shield around the seal. Remove it.
  2.  



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Fig. Fig. 1: Installing the output shaft seal



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Fig. Fig. 2: Transfer case and components-NP241



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Fig. Fig. 3: Transfer case and components-BW 4401 and BW 4470

  1. Using a hammer and a punch, carefully distort the seal so that you can pull it out with a pliers. Be careful to avoid damage to the seal bore!
  2.  

To install:
  1. Coat the seal lips with clean oil fluid. Coat the outer edge of the seal with gasket sealer.
  2.  
  3. Position the seal in the bore and drive it into place by carefully tapping around it with a hammer. If you have access to one, a seal installer will make the job a little easier.
  4.  
  5. Install the shield, if used.
  6.  
  7. Coat the outer surface of the yoke neck with clean oil and slide it into place.
  8.  
  9. Install the nut and washer. Tighten the nut to:

    NP205: 150 ft. lbs. (203 Nm)
     
    NP208: 120 ft. lbs. (163 Nm)
     
    NP241: 110 ft. lbs. (149 Nm)
     
    NVG243: 110 ft. lbs. (149 Nm)
     
    BW 1370, BW 4401, BW 4470 front: 165 ft. lbs. (225 Nm)
     
    BW 1370, BW 4401, BW 4470 rear: 125 ft. lbs. (170 Nm)
     

  10.  
  11. Install the driveshaft.
  12.  
  13. Install the skid plate.
  14.  

 
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