Lexus GS, SC 1998-06

Camshaft, Bearings & Lifters 5

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Removal & Installation



4.3L (3UZ-FE) Engines (2004)
  1. Before servicing the vehicle, refer to the Precautions section.
  2.  
  3. Relieve the fuel pressure from the fuel lines.
  4.  
  5. Remove or disconnect the following:

    Engine under cover
     
    Drain engine coolant and engine oil
     
    V-bank cover
     
    Air cleaner assembly
     
    Intake air pipe
     
    Radiator
     
    Throttle body
     
    Upper and lower intake manifold assembly
     
    Timing belt from camshaft pulleys
     
    Camshaft position sensor and LH timing belt rear plates
     
    RH timing belt rear plates
     

  6.  


WARNING
Do NOT drop anything inside timing belt cover during this procedure. Keep oil, water and dust from timing belt.



Power steering pump from engine mount (Do NOT disconnect hoses)
 
Catalytic converters
 
Water inlet housing assembly
 
Water bypass pipe, front bypass joint, and rear bypass joint
 
Ignition coils
 
Variable valve timing (VVT) sensors
 
Engine hangers
 
Oil dipsticks and guides for engine oil and transmission fluid
 
Cylinder head covers
 
Spark plugs
 
Semi-circular plugs and camshaft housing plugs
 
Camshaft timing oil control valve
 


WARNING
Since the thrust clearance of the camshaft is small, the camshaft must be kept level during removal steps. If it is not kept level, the portion of the cylinder head receiving the shaft thrust may crack or be damaged, causing the camshaft to later seize or break. Follow the procedure carefully to avoid this damage.

  1. Check the crankshaft pulley position and ensure the timing mark of the pulley is aligned with the centers of the crankshaft pulley bolt and the No. 2 timing belt idler pulley bolt.
  2.  


WARNING
Having the crankshaft pulley at the wrong angle can cause the piston head and valve head to come into contact with each other during camshaft removal. Always set the crankshaft pulley at the described angle.

  1. Using a special wrench, rotate the camshaft timing tube from left to right about 2-3 times, within only a 25°range of movement. Use a waste cloth to collect oil from the camshaft timing oil control valve installation hole.
  2.  
  3. Remove the LH camshafts first. With a hex wrench on the hex portion of the camshaft, rotate so that a 6mm service bolt can be inserted into the bolt hole in the rear face of the camshaft pulley into order to secure the camshaft in place. The bolt should be about 0.63-0.79 in. (16-20mm) long.
  4.  
  5. Align the timing mark (2 dots) of the camshaft drive gear by turning the camshaft with a hex wrench until the timing mark aligns.
  6.  
  7. Now, uniformly loosen the 22 camshaft bearing cap bolts, in several passes, following the sequence shown.
  8.  
  9. Remove the 22 bearing cap bolts, 4 seal washers, oil feed pipe, 9 bearing caps, the camshaft housing plug, the oil control valve filter, and both LH camshafts. Keep all parts in order for proper reinstallation.
  10.  
  11. Remove the RH camshafts. With a hex wrench on the hex portion of the camshaft, rotate so that a 6mm service bolt can be inserted into the bolt hole in the rear face of the camshaft pulley into order to secure the camshaft in place. The bolt should be about 0.63-0.79 in. (16-20mm) long.
  12.  
  13. Align the timing mark (1 dot) of the camshaft main gear about 10° angle by turning the camshaft with a hex wrench until the timing mark aligns.
  14.  
  15. Now, uniformly loosen the 22 camshaft bearing cap bolts, in several passes, following the sequence shown.
  16.  
  17. Remove the 22 bearing cap bolts, 4 seal washers, oil feed pipe, 9 bearing caps, the camshaft housing plug, the oil control valve filter, and both LH camshafts. Keep all parts in order for proper reinstallation.
  18.  


    Click image to see an enlarged view

    Fig. LH camshaft bearing cap bolt loosening sequence-4.3L (3UZ-FE) Engine (2004 Model)



    Click image to see an enlarged view

    Fig. RH camshaft bearing cap bolt loosening sequence-4.3L (3UZ-FE) Engine (2004 Model)


To install:


WARNING
Since the thrust clearance of the camshaft is small, the camshaft must be kept level during removal steps. If it is not kept level, the portion of the cylinder head receiving the shaft thrust may crack or be damaged, causing the camshaft to later seize or break. Follow the procedure carefully to avoid this damage.

  1. Ensure the crankshaft pulley is in position so that its timing mark is in line with the centers of the pulley bolt and idler pulley bolt.
  2.  


WARNING
Having the crankshaft pulley at the wrong angle can cause the piston head and valve head to come into contact with each other during camshaft removal. Always set the crankshaft pulley at the described angle.

  1. Apply grease to the thrust portion of the LH intake and exhaust camshafts. Align the timing marks (2 dots) of the camshaft drive and driven main gears. Place the camshafts into the LH cylinder head.
  2.  
  3. Apply new seal packing material around the opening of the camshaft housing plug. Install the camshaft housing plug and the oil control valve filter into the cylinder head, as shown.
  4.  
  5. Remove any old packing material, then install new packing material around the mounting edge (not in the grooves) of the front bearing cap.
  6.  
  7. Position the front bearing cap in place. This will determine the thrust portion of the camshaft.
    1. Install the other bearing caps, in sequence shown, with the arrow marks facing forward.
    2.  
    3. Push the camshaft oil seal into place by pushing from the front of the engine. Install a new seal washer to the front bearing cap bolts.
    4.  
    5. Apply a light coat of oil to bearing cap bolt threads and under the heads of the bearing cap bolts -D- and -E-, as shown. Do NOT apply engine oil under the heads of bearing cap bolts -A-, -B- and -C-.
    6.  
    7. Bolt lengths vary for each bearing cap. Refer to the illustration for each of the following bolts:
    8.  
    9. Bolt -A- with seal washer is 3.70 in. (94mm)
    10.  
    11. Bolt -B- with seal washer is 2.83 in. (72mm)
    12.  
    13. Bolt -C- is 0.98 in. (25mm)
    14.  
    15. Bolt -D- is 2.05 in. (52mm)
    16.  
    17. Bolt -E- is 1.50 in. (38mm)
    18.  

  8.  
  9. Install the oil feed pipe and the 22 bearing cap bolts in their respective locations. Uniformly tighten the 22 bearing cap bolts, in several passes, following the sequence as shown. Torque bolt -C- to a final torque of 66 inch lbs. (7.5 Nm). Torque all other bearing cap bolts to a final torque of 12 ft. lbs. (16 Nm).
  10.  
  11. Remove the service bolt installed in the rear face of the gear.
  12.  
  13. Repeat this entire procedure for the RH camshafts. Use the illustrations given for the LH camshafts, as the sequences are the same on the RH camshafts.
  14.  
  15. Check and adjust valve lash. See VALVE LASH.
  16.  
  17. Install or reconnect the following:

    Camshaft timing oil control valve.
     
    Semi-circular plugs in rear ends of each cylinder head
     
    Cylinder head covers, with new gaskets and packing material
     
    Engine hangers
     
    Variable valve timing sensors
     
    Oil dipsticks and tubes
     
    All remaining components in reverse of removal procedure.
     

  18.  


    Click image to see an enlarged view

    Fig. Installing the camshaft housing plug and oil control valve filter for the LH camshaft-4.3L (3UZ-FE) Engine (2004 Model)



    Click image to see an enlarged view

    Fig. Installing the camshaft bearing caps in sequence on the LH camshaft-4.3L (3UZ-FE) Engine (2004 Model)



    Click image to see an enlarged view

    Fig. Identifying the locations of camshaft bearing caps on the LH camshaft-4.3L (3UZ-FE) Engine (2004 Model)



    Click image to see an enlarged view

    Fig. Identifying the locations of camshaft bearing caps on the LH camshaft-4.3L (3UZ-FE) Engine (2004 Model)


 
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