GM Full-Size Trucks 1988-1998 Repair Information

Balance Shaft

Print

REMOVAL & INSTALLATION



See Figures 1, 2, 3 and 4

The procedure applies to 1994-98 4.3L engines only.



Click image to see an enlarged view

Fig. Fig. 1: View of the balance shaft drive and driven gears



Click image to see an enlarged view

Fig. Fig. 2: View of the balance shaft location-1994-98 4.3L engine



Click image to see an enlarged view

Fig. Fig. 3: Unfasten the balance shaft gear bolt...



Click image to see an enlarged view

Fig. Fig. 4: ... then remove the gear


CAUTION
Never open, service or drain the radiator or cooling system when hot; serious burns can occur from the steam and hot coolant. Also, when draining engine coolant, keep in mind that cats and dogs are attracted to ethylene glycol antifreeze and could drink any that is left in an uncovered container or in puddles on the ground. This will prove fatal in sufficient quantities. Always drain coolant into a sealable container. Coolant should be reused unless it is contaminated or is several years old.

  1. Have the air conditioning system discharged by a qualified technician using a proper refrigerant recovery/recycling station.
  2.  
  3. Properly relieve the fuel system pressure, then disconnect the negative battery cable.
  4.  
  5. Remove the air cleaner intake duct.
  6.  
  7. Drain the engine cooling system.
  8.  
  9. Remove the A/C compressor and its brackets.
  10.  
  11. Remove the radiator and air conditioning condenser from the vehicle.
  12.  
  13. Remove the fan assembly.
  14.  
  15. Carefully release the belt tension, then remove the serpentine drive belt.
  16.  
  17. Remove the water pump.
  18.  
  19. Remove the crankshaft pulley and damper.
  20.  
  21. Drain the oil and remove the oil pan.
  22.  
  23. Remove the front cover.
  24.  
  25. Remove the timing chain and sprockets.
  26.  
  27. Unfasten the balance shaft gear bolt, then remove the gear.
  28.  
  29. Remove the balance shaft retainer.
  30.  
  31. Remove the intake manifold assembly.
  32.  
  33. Remove the hydraulic lifter retainer.
  34.  
  35. Remove the balance shaft and front bearing by gently driving them out using a soft faced mallet.
  36.  
  37. Using tool J-38834 or its equivalent, remove the balance shaft rear bearing.
  38.  

The balance shaft and drive and driven gears are serviced only as a set, including the gear bolt. The balance shaft and front bearing are serviced as a package.


WARNING
The front bearing must not be removed from the balance shaft

To install:
  1. Inspect the balance shaft gears for damage, such as nicks and burrs.
  2.  
  3. Using a suitable gasket scraper, clean the gasket mounting surfaces. Using solvent, clean the oil and grease from the gasket mounting surfaces.
  4.  
  5. Lubricate the balance shaft rear bearing with clean engine oil, then install the bearing using tool J-38834 or its equivalent.
  6.  
  7. Lubricate the balance shaft with clean engine oil, then install the balance shaft into the block.
  8.  
  9. Install the balance shaft bearing retainer and bolts. Tighten the bolts to 106 inch. lbs. (12 Nm).
  10.  
  11. Install the balance shaft driven gear and bolt. Tighten the bolt to 15 ft. lbs. (20 Nm) plus an additional 35° using a torque/angle meter.
  12.  
  13. Install the hydraulic lifter retainer, then rotate the balance shaft by hand and check that there is clearance between the balance shaft and the lifter retainer.
  14.  
  15. Temporarily install the balance shaft drive gear so that the timing mark on the gear points straight up, then remove the drive gear, turn the balance shaft so the timing mark on the driven gear is facing straight down.
  16.  
  17. Install the drive gear and make sure the timing marks on both gears line up (dot-to-dot).
  18.  
  19. Install the drive gear retaining bolt and tighten to 12 ft. lbs. (16 Nm).
  20.  
  21. Install the intake manifold assembly.
  22.  
  23. Install the timing chain and sprocket assemblies.
  24.  
  25. Install the front cover, seal, bolts and the oil pan assembly.
  26.  
  27. Using tool J-39046 or its equivalent engage the crankshaft pulley and damper.
  28.  
  29. Install the water pump.
  30.  
  31. Install the serpentine drive belt.
  32.  
  33. Install the fan assembly.
  34.  
  35. Install the air conditioning condenser and the radiator assemblies. Engage all hoses removed from the radiator.
  36.  
  37. Install the A/c compressor.
  38.  
  39. Engage the oil and transmission cooler lines at the radiator, then install the radiator shroud.
  40.  
  41. Install the air cleaner assembly and connect the negative battery cable.
  42.  
  43. Fill the crankcase with the correct grade and amount of oil.
  44.  
  45. Fill the cooling system with coolant.
  46.  
  47. Start the vehicle and check for leaks.
  48.  
  49. Have the air conditioning system charged by a qualified technician using a proper refrigerant recovery/recycling station.
  50.  

 
label.common.footer.alt.autozoneLogo