GM Full Size Vans 1987-1997 Repair Guide

Timing Chain Cover and Seal

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REMOVAL & INSTALLATION



4.3L, 5.0L and 5.7L Engines

See Figures 1 through 10



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Fig. Fig. 1: Loosen and remove the timing cover retaining bolts ...



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Fig. Fig. 2: ... then carefully break the gasket seal ...



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Fig. Fig. 3: ... remove the cover from the engine compartment

  1. Drain the cooling system.
  2.  
  3. Drain the oil and remove the oil pan.
  4.  
  5. Remove the crankshaft pulley and damper.
  6.  
  7. Remove the water pump.
  8.  
  9. If equipped, remove the crankshaft position sensor.
  10.  
  11. Remove the bolts holding the timing case cover to the block and remove the cover and gaskets.
  12.  
  13. Use a suitable tool to pry the old seal out of the front face of the cover.
  14.  



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Fig. Fig. 4: Using a seal puller, remove the old seal from the front cover:

To install:
  1. Install the new seal so that the open end is toward the inside of the cover.
  2.  

Coat the lip of the new seal with oil prior to installation.

  1. Check that the timing chain oil slinger is in place against the crankshaft sprocket.
  2.  
  3. Apply sealer to the front cover as shown in the accompanying illustration. Install the cover carefully onto the locating dowels.
  4.  
  5. On 1987-95 models, tighten the attaching screws to 124 inch lbs. (14 Nm) on the 4.3L and 100 inch lbs. (11 Nm) on the 5.0L and 5.7L.
  6.  
  7. On 1996-97 models, tighten the attaching screws to 106 inch lbs. (12 Nm) on the 4.3L, 5.0L and 5.7L models.
  8.  
  9. Install the remaining components and fill the engine with oil and coolant. Road test the van.
  10.  



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Fig. Fig. 5: Oil pan front seal modification



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Fig. Fig. 6: Front seal installed



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Fig. Fig. 7: Sealer application



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Fig. Fig. 8: Cutting the seal



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Fig. Fig. 9: Guiding the cover into place. Make sure the seal remains undisturbed

7.4L Engines

Special tool J-22102, or its equivalent seal driver, will be necessary for this job.

  1. Disconnect the negative battery cable.
  2.  
  3. Drain the cooling system.
  4.  
  5. Remove the water pump.
  6.  
  7. Remove the crankshaft pulley and damper.
  8.  
  9. If equipped, remove the crankshaft position sensor.
  10.  
  11. Remove the oil pan.
  12.  
  13. Remove the front cover bolts.
  14.  
  15. Pull off the cover and gaskets.
  16.  
  17. Use a suitable tool to pry the old seal out of the front face of the cover.
  18.  

To install:
  1. Using seal driver J-22102, or equivalent, install the new seal so that the open end is toward the inside of the cover.
  2.  

Coat the lip of the new seal with oil prior to installation.

  1. Install a new front pan seal, cutting the tabs off.
  2.  
  3. Coat a new cover gasket with adhesive sealer and position it on the block.
  4.  
  5. Apply a 1 / 8 in. (bead of RTV gasket material to the front cover. Install the cover carefully onto the locating dowel.
  6.  
  7. On 1987-95 models, tighten the retaining bolts to 100 inch lbs. (11 Nm).
  8.  
  9. On 1996-97 models, tighten the retaining bolts to 89 inch lbs. (10 Nm).
  10.  
  11. Install the oil pan.
  12.  
  13. If removed, install the crankshaft position sensor.
  14.  
  15. Install the damper.
  16.  
  17. Install the water pump.
  18.  
  19. Fill the crankcase with the proper amount and grade of engine oil.
  20.  
  21. Connect the battery cables and fill the cooling system.
  22.  

6.2L and 6.5L Diesel Engines

See Figure 6

  1. Drain the cooling system.
  2.  
  3. Remove the water pump.
  4.  
  5. Rotate the crankshaft to align the marks on the injection pump driven gear and the camshaft gear as shown in the illustration.
  6.  
  7. Scribe a mark aligning the injection pump flange and the front cover.
  8.  
  9. Remove the crankshaft pulley and torsional damper.
  10.  
  11. If equipped, remove the crankshaft position sensor.
  12.  
  13. Remove the front cover-to-oil pan bolts (4).
  14.  



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Fig. Fig. 10: Front cover installation showing sealer application - diesel engines

  1. Remove the two fuel return line clips.
  2.  
  3. Remove the injection pump retaining nuts from the front cover.
  4.  
  5. Remove the baffle. Remove the remaining cover bolts, and remove the front cover.
  6.  
  7. If the front cover oil seal is to be replaced, it can now be pried out of the cover with a suitable prying tool. Press the new seal into the cover evenly.
  8.  

The oil seal can also be replaced with the front cover installed. Remove the torsional damper first, then pry the old seal out of the cover using a suitable prying tool. Use care not to damage the surface of the crankshaft. Install the new seal evenly into the cover and install the damper.

To install:
  1. To install the front cover, first clean both sealing surfaces until all traces of old sealer are gone. Apply a 3 / 32 in. (2mm) bead of sealant (GM sealant #1052357 or equivalent) to the sealing surface as shown in the illustration. Apply a bead of RTV type sealer to the bottom portion of the front cover which attached to the oil pan. Install the front cover.
  2.  
  3. Install the baffle.
  4.  
  5. Install the injection pump, making sure the scribe marks on the pump and front cover are aligned.
  6.  
  7. Install the injection pump driven gear, making sure the marks on the cam gear and pump are aligned. Be sure the dowel pin and the three holes on the pump flange are also aligned.
  8.  
  9. Install the fuel line clips, the front cover-to-oil bolts, and the torsional damper and crankshaft pulley. Tighten the cover-to-block bolts to 33 ft. lbs. (45 Nm) on 1987-95 models and 30 ft. lbs. (40 Nm).
  10.  
  11. If equipped, tighten the baffle bolts and nut to 33 ft. lbs. (45 Nm), the injection pump nuts to 31 ft. lbs. (42 Nm) and the injection pump bolts to 17 ft. lbs. (23 Nm).
  12.  

 
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