Liberty, Wrangler, 1997-2005

Balance Shaft

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Removal & Installation



2.4L Engines


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Fig. Balance shafts and carrier-2.4L engines

  1. Before servicing the vehicle, refer to the Precautions section.
  2.  
  3. Drain engine oil.
  4.  
  5. Remove the oil pan.
  6.  
  7. Remove chain cover, guide and tensioner.
  8.  
  9. Remove gear cover retaining stud (double ended to also retain chain guide). Remove cover and balance shaft gears.
  10.  
  11. Remove balance shaft gear, chain sprocket retaining screws, and crankshaft chain sprocket. Remove chain and sprocket assembly. Using two wide pry bars, work the sprocket back and forth until it is off the shaft.
  12.  
  13. Remove carrier gear cover and balance shafts.
  14.  
  15. Remove four carrier to crankcase attaching bolts to separate carrier from engine bedplate.

    Click image to see an enlarged view

    Fig. Balance shaft chain cover, guide and tensioner-2.4L engines



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    Fig. Balance shaft gear cover and gears-2.4L engines



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    Fig. Balance shaft chain and sprockets-2.4L engines



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    Fig. Balance shaft removal-2.4L engines



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    Fig. Balance shaft installation-2.4L engines



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    Fig. Balance shaft gear timing-2.4L engines



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    Fig. Balance shaft drive sprocket installation-2.4L engines

  16.  

Balance Shaft Carrier

NOTE
The following components will remain intact during carrier removal. Gear cover, gears, balance shafts and the rear cover.

  1. Remove chain cover and driven balance shaft chain sprocket screw.
  2.  
  3. Loosen tensioner pivot and adjusting screws, move driven balance shaft inboard through driven chain sprocket. Sprocket will hang in lower chain loop.
  4.  
  5. Remove carrier to crankcase attaching bolts to remove carrier.
  6.  

To install:

  1. Balance shaft and carrier assembly installation is the reverse of the removal procedure. During installation crankshaft-to-balance shaft timing must be established. Timing is performed as follows:
  2.  
  3. With balance shafts installed in carrier position carrier on crankcase and install four attaching bolts and tighten to 40 ft. lbs. (54 Nm).
  4.  
  5. Turn balance shafts until both shaft key ways are up, parallel to vertical centerline of engine. Install short hub drive gear on sprocket driven shaft and long hub gear on gear driven shaft. After installation gear and balance shaft keyways must be up with gear timing marks meshed as shown in.
  6.  
  7. Install gear cover and tighten double ended stud/washer fastener to 105 inch lbs. (12 Nm).
  8.  
  9. Align flat on balance shaft drive sprocket to the flat on crankshaft.
  10.  
  11. Install balance shaft drive sprocket on crankshaft using Special Tool 6052, or equivalent.
  12.  
  13. Turn crankshaft until number 1 cylinder is at top dead center (TDC). The timing marks on the chain sprocket should line up with the parting line on the left side of number one main bearing cap.
  14.  
  15. Place chain over crankshaft sprocket so that the plated link of the chain is over the number 1 cylinder timing mark on the balance shaft crankshaft sprocket.
  16.  
  17. Place balance shaft sprocket into the timing chain and align the timing mark on the sprocket (dot) with the (lower) plated link on the chain.
    NOTE
    The lower plated link is 8 links from the upper link.

  18.  
  19. With balance shaft keyways pointing up (12 o-clock) slide the balance shaft sprocket onto the nose of the balance shaft. The balance shaft may have to be pushed in slightly to allow for clearance.
  20.  
  21. If the sprockets are timed correctly, install the balance shaft bolts and tighten to 250 inch lbs. (28 Nm). A wood block placed between crankcase and crankshaft counterbalance will prevent crankshaft and gear rotation.

    Click image to see an enlarged view

    Fig. Balance shaft timing-2.4L engines

  22.  

Chain Tensioning


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Fig. Balance shaft chain tension adjustment-2.4L engines

  1. Install chain tensioner loosely assembled.
  2.  
  3. Position guide on double ended stud making sure tab on the guide fits into slot on the gear cover. Install and tighten nut/washer assembly to 105 inch lbs. (12 Nm).
  4.  
  5. Place a shim 0.039 in.(1 mm) thick x 2.75 in. (70 mm) long or between tensioner and chain. Push tensioner and shim up against the chain. Apply firm pressure 5.5-6.6 lbs. (2.5-3 Kg) directly behind the adjustment slot to take up all slack. Chain must have shoe radius contact as shown.
  6.  
  7. With the load applied, tighten top tensioner bolt first, then bottom pivot bolt. Tighten bolts to 105 inch lbs. (12 Nm). Remove shim.
  8.  
  9. Install carrier covers and tighten screws to 105 inch lbs. (12 Nm).
  10.  
  11. Install pick-up tube and oil pan.
  12.  
  13. Fill engine crankcase with proper oil to correct level.
  14.  

2.8L Engine


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Fig. Oil pick up tube and balance shaft assembly

  1. Disconnect negative battery cable.
  2.  
  3. Raise vehicle on hoist.
  4.  
  5. Remove oil pan.
  6.  
  7. Remove oil pump pickup tube.
  8.  
  9. Remove balance shaft assembly and discard O-rings on the central carrier pins.
  10.  

To install:

Click image to see an enlarged view

Fig. Balance shaft alignment


CAUTION
Install new O-rings on the carrier pins and oil pick up tube before assembly.


NOTE
Before installation of the balance shaft assembly, the # 1 cylinder must be brought to TDC, or the 12 O'clock position. There is a line on the front of the crankshaft hub, next to the front crankshaft bolt, that may assist the alignment .

  1. Remove the vibration damper and roll engine over by hand until the witness line on the front of the crankshaft hub is at the 12 O'clock, or TDC position. Once the # 1 cylinder is brought to TDC, the balance shaft assembly can be installed.
    CAUTION
    Care must be taken during the installation of the drift or punch. The back side of the counter weights on the balance shafts must be in the up position before inserting the tool into the housing.

  2.  
  3. With balance shaft assembly on work bench. Insert a drift of a punch into balance shaft assembly alignment hole. This will ensure proper balance shaft to crankshaft timing after assembly.
  4.  
  5. Install the new crankshaft carrier pin O-rings, balance shaft assembly and retaining bolts . Torque bolts to 24 ft. lbs. (32.4 Nm), and remove the punch from the alignment hole.
  6.  
  7. Install oil pump pickup tube with new seals.
  8.  
  9. Install oil pan.
  10.  
  11. Refill engine oil to proper level.
  12.  
  13. Connect negative battery cable.
  14.  

3.7L Engine


Click image to see an enlarged view

Fig. The balance shaft retaining plate on the 3.7L engine

  1. Remove the primary and secondary timing chains.
    NOTE
    The balance shaft and gear are serviced as an assembly. Do not attempt to remove the gear from the balance shaft. Remove the retaining bolt from the counterbalance shaft thrust plate.

  2.  
  3. Using Special Tool 8641 Counterbalance shaft remover/installer tool, remove the counterbalance shaft from the engine .
  4.  

To install:


NOTE
The balance shaft and gear are serviced as an assembly. Do not attempt to remove the gear from the balance shaft.

  1. Coat counterbalance shaft bearing journals with clean engine oil.
    NOTE
    The balance shaft is heavy, and care should be used when installing shaft, so bearings are not damaged.

  2.  
  3. Using Special Tool 8641 Counterbalance shaft remover/installer tool, carefully install counterbalance shaft into engine .
  4.  
  5. Install Counterbalance shaft thrust plate retaining bolt finger tight. Do not tighten bolt at this time.
  6.  
  7. Position the right side of the thrust plate with the right chain guide bolt, install bolt finger tight.
  8.  
  9. Torque the thrust plate retaining bolt to 250 inch lbs. (28 Nm).
  10.  
  11. Remove the chain guide bolt so that guide can be installed.
  12.  

4.0L Engine
  1. Drain engine oil.
  2.  
  3. Remove the oil pan and pick-up tube.
  4.  
  5. If replacing crankshaft sprocket, remove oil pump.
  6.  
  7. Remove chain cover, guide and tensioner. Discard pivot screw and adjuster screw.
  8.  
  9. Remove screw retaining balance shaft drive sprocket. Remove chain and sprocket.
  10.  
  11. Using two wide pry bars, work the crankshaft sprocket back and forth until it is off the crankshaft shaft.
  12.  
  13. Remove gear cover retaining stud (double ended to also retain chain guide). Remove cover and balance shaft gears.
  14.  
  15. Remove rear cover and balance shafts.
  16.  
  17. Remove four carrier to crankcase attaching bolts to separate carrier from engine bedplate
  18.  

To install:

Balance shaft and carrier assembly installation is the reverse of the removal procedure. During installation crankshaft-to-balance shaft timing must be established.

  1. With balance shafts installed in carrier position carrier on crankcase and install four attaching bolts and tighten to 40 ft. lbs. (54 Nm).
  2.  
  3. Turn balance shafts until both shaft key ways are up, parallel to vertical centerline of engine
  4.  
  5. Install short hub drive gear on sprocket driven shaft and long hub gear on gear driven shaft. After installation gear and balance shaft keyways must be up with gear timing marks meshed as shown in.
  6.  
  7. Install gear cover and tighten double ended stud/washer fastener to 105 inch lbs. (12 Nm.).
  8.  
  9. Align flat on balance shaft drive sprocket to the flat on crankshaft.
  10.  
  11. Install balance shaft drive sprocket on crankshaft using Special Tool 6052.
  12.  
  13. Turn crankshaft until number 1 cylinder is at top dead center (TDC). The timing marks on the chain sprocket should line up with the parting line on the left side of number one main bearing cap.
  14.  
  15. Place chain over crankshaft sprocket so that the plated link of the chain is over the number 1 cylinder timing mark on the balance shaft crankshaft sprocket.
  16.  
  17. Place balance shaft sprocket into the timing chain and align the timing mark on the sprocket (dot) with the (lower) plated link on the chain
    NOTE
    The lower plated link is 8 links from the upper link.

  18.  
  19. With balance shaft keyways pointing up. (12 o-clock) slide the balance shaft sprocket onto the nose of the balance shaft. The balance shaft may have to be pushed in slightly to allow for clearance
    NOTE
    The timing mark on the sprocket, the (lower) nickel-plated link, and the arrow on the side of the gear cover should line up when the balance shafts are timed correctly.

  20.  
  21. If the sprockets are timed correctly, install the balance shaft bolts and tighten to 250 in lbs.28 (Nm). A wood block placed between crankcase and crankshaft counterbalance will prevent crankshaft and gear rotation.
  22.  
  23. Chain Tensioning:
    1. Install chain tensioner loosely assembled with new adjuster screw and shouldered pivot screw.
    2.  
    3. Position guide on double ended stud making sure tab on the guide fits into slot on the gear cover. Install and tighten nut/washer assembly to 105 inch lbs. (12 Nm).
    4.  
    5. Place a shim 0.039 in. (1 mm) thick x 2.75 in. (70 mm) long between tensioner and chain. Push tensioner and shim up against the chain. Apply firm pressure 5.5-6.6 lbs. (2.5-3 Kg) directly behind the adjustment slot to take up all slack. Chain must have shoe radius contact as shown in.
    6.  
    7. With the load applied, tighten top tensioner adjuster bolt first, then bottom shouldered pivot bolt. Tighten bolts to 105 inch lbs. (12 Nm). Remove shim.
    8.  
    9. Install carrier covers and tighten screws to 105 inch lbs. (12 Nm).
    10.  

  24.  
  25. If removed, install oil pump.
  26.  
  27. Install pick-up tube and oil pan.
  28.  
  29. Fill engine crankcase with proper oil to correct level
  30.  

 
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