Lexus GS, SC 1998-06

Camshaft, Bearings & Lifters 2

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Removal & Installation



3.0L (1MZ-FE) Engine
  1. Before servicing the vehicle, refer to the Precautions section.
  2.  
  3. Remove or disconnect the following:

    Timing belt and idler pulley
     
    Camshaft timing pulleys
     
    Cylinder head covers
     

  4.  


WARNING
The thrust clearance on both the intake and exhaust camshafts is very small, the camshafts must be kept level during removal. If the camshafts are removed without being kept level, the camshaft may be caught in the cylinder head causing the head to break or the camshaft to seize.

  1. To remove the exhaust and intake camshafts from the right side cylinder head:
    1. Turn the camshaft with a wrench until the 2 pointed marks drive and driven gears are aligned. (The right camshaft gears have 2 marks apiece; the left side camshaft gears have 1 mark each.)
    2.  
    3. Secure the exhaust camshaft subgear to the main gear using a service bolt. A bolt 0.63-0.79 in. (16-20mm) long with a 6mm thread diameter and a 1mm pitch is recommended. When removing the exhaust camshaft be sure the subgear is not loaded; all the force must be eliminated.
    4.  
    5. Uniformly loosen and remove the exhaust camshaft bearing cap bolts in several passes and in the proper sequence. Remove the 8 bearing cap bolts and remove the caps, keeping them in the correct order.
    6.  
    7. Remove the exhaust camshaft from the engine.
    8.  
    9. Uniformly loosen and remove the 10 bearing cap bolts in several passes, in the proper sequence. Remove the bearing caps, keeping them in order, remove the oil seal, then lift out the intake camshaft.
    10.  



    Click image to see an enlarged view

    Fig. Aligning the right side camshaft timing marks-3.0L (1MZ-FE) engine



    Click image to see an enlarged view

    Fig. Securing the subgear and driven gear, right side-3.0L (1MZ-FE) engine

  2.  
  3. To remove the exhaust and intake camshafts from the left side cylinder head:
    1. Turn the camshaft with a wrench until the pointed marks on the drive and driven gears are aligned. (The right camshaft gears have 2 marks apiece; the left side camshaft gears have 1 mark each.)
    2.  
    3. Secure the exhaust camshaft subgear to the main gear using a service bolt. A bolt 0.63-0.79 in. (16-20mm) long with a 6mm thread diameter and a 1mm pitch is recommended. When removing the exhaust camshaft be sure the subgear is not loaded; all the force must be eliminated.
    4.  
    5. Uniformly loosen and remove the exhaust camshaft bearing cap bolts in several passes and in the proper sequence. Remove the 8 bearing cap bolts and remove the caps. Keep the caps in the correct order.
    6.  
    7. Remove the exhaust camshaft from the engine.
    8.  
    9. Uniformly loosen and remove the 10 bearing cap bolts in several passes, in the proper sequence. Remove the bearing caps, keeping them in order, remove the oil seal, then lift out the intake camshaft.
    10.  

  4.  
  5. Remove the valve lash adjuster shims and hydraulic lash adjusters. Identify each lash adjuster and shim as it is removed so it can be reinstalled in the same position. If the lash adjusters are to be reused, store them upside down in a sealed container.
  6.  


    Click image to see an enlarged view

    Fig. Right exhaust camshaft bearing loosening sequence-3.0L (1MZ-FE) engine



    Click image to see an enlarged view

    Fig. Right intake camshaft bearing loosening sequence-3.0L (1MZ-FE) engine



    Click image to see an enlarged view

    Fig. Aligning the left side camshaft timing marks-3.0L (1MZ-FE) engine



    Click image to see an enlarged view

    Fig. Securing the subgear and driven gear, left side-3.0L (1MZ-FE) engine



    Click image to see an enlarged view

    Fig. Left intake camshaft bearing cap bolt loosening sequence-3.0L (1MZ-FE) engine



    Click image to see an enlarged view

    Fig. Left exhaust camshaft bearing cap bolt loosening sequence-3.0L (1MZ-FE) engine


To install:

  1. Install or connect the following:

    Valve lash adjusters and shims. Check valve clearance and replace the shims as necessary.
     

  2.  


NOTE
Before installing the camshafts in either cylinder head, apply multi-purpose grease to the thrust portions of each camshaft.

  1. To install the right camshafts:
    1. Position the intake camshaft on the head so that the alignment marks are at a 90°angle from vertical. The mark should be at the 3 o'clock position.
    2.  
    3. Apply sealant to the No. 1 bearing cap.
    4.  
    5. Apply a light coat of clean engine oil to the bolt threads and under the bolt head. Install the bearing caps to their proper position. Tighten the bolts evenly and in several passes in the reverse order of loosening to 12 ft. lbs. (16 Nm) in the proper sequence.
    6.  
    7. Position the exhaust camshaft on the head so that the alignment marks are at a 90°angle from vertical. The mark should be at the 9 o'clock position and must align with the marks on the other gear.
    8.  
    9. Apply a light coat of clean engine oil to the bolt threads and under the bolt head. Install the bearing caps to their proper position. Tighten the bolts evenly and in several passes in the reverse order of loosening to 12 ft. lbs. (16 Nm) in the proper sequence.
    10.  
    11. Remove the service bolt.
    12.  



    Click image to see an enlarged view

    Fig. Exhaust camshaft installation position on the right cylinder head-3.0L (1MZ-FE) engine



    Click image to see an enlarged view

    Fig. Exhaust camshaft bearing cap bolt tightening sequence on the right cylinder head-3.0L (1MZ-FE) engine



    Click image to see an enlarged view

    Fig. Intake camshaft installation position on the right cylinder head-3.0L (1MZ-FE) engine



    Click image to see an enlarged view

    Fig. Intake camshaft bearing cap bolt tightening sequence on the right cylinder head-3.0L (1MZ-FE) engine

  2.  
  3. To install the left camshafts:
    1. Position the intake camshaft on the head so that the alignment mark is at a 90 degree angle from vertical. The mark should be at the 9 o'clock position.
    2.  
    3. Apply sealant to the No. 1 bearing cap.
    4.  
    5. Apply a light coat of clean engine oil to the bolt threads and under the bolt head. Install the bearing caps to their proper position. Tighten the bolts evenly and in several passes to 12 ft. lbs. (16 Nm) in the proper sequence.
    6.  
    7. Position the exhaust camshaft on the head so that the alignment marks are at a 90-degree angle from vertical. The mark should be at the 3 o'clock position and must align with the marks on the other gear.
    8.  
    9. Apply a light coat of clean engine oil to the bolt threads and under the bolt head. Install the bearing caps to their proper position. Tighten the bolts evenly and in several passes to 12 ft. lbs. (16 Nm) in the proper sequence.
    10.  
    11. Remove the service bolt.
    12.  

  4.  
  5. Apply multi-purpose grease to new camshaft oil seals. Install the seals.
  6.  
  7. Install or connect the following:

    No. 3 (rear) timing belt cover
     
    Camshaft timing gears
     
    Idler pulley, timing belt and covers
     

  8.  
  9. Check and adjust the valve clearance.
  10.  
  11. Install the cylinder head (valve) covers.
  12.  


    Click image to see an enlarged view

    Fig. Exhaust camshaft installation position on the left cylinder head-3.0L (1MZ-FE) engine



    Click image to see an enlarged view

    Fig. Exhaust camshaft bearing cap bolt tightening sequence on the right cylinder head-3.0L (1MZ-FE) engine



    Click image to see an enlarged view

    Fig. Intake camshaft installation position on the left cylinder head-3.0L (1MZ-FE) engine



    Click image to see an enlarged view

    Fig. Intake camshaft bearing cap bolt tightening sequence on the right cylinder head-3.0L (1MZ-FE) engine


 
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