Avalon 1995-1996

Camshaft & Lifters

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Inspection



Specific to:

Toyota Avalon 1995-1996

  1. Before servicing the vehicle, refer to the Precautions Section.
  2.  
  3. Place the camshaft on V-blocks.
  4.  
  5. Inspect the camshaft runout:
    1. Using a dial indicator, measure the circle runout at the center journal. Maximum circle runout: 0.0024 in. (0.06 mm)

      Click image to see an enlarged view

      Fig. Inspect camshaft runout

    2.  
    3. If the circle runout is greater than maximum, replace the camshaft.
    4.  

  6.  
  7. Inspect the cam lobes:
    1. Using a micrometer, measure the cam lobe height.
    2.  
    3. Standard cam lobe height:

      Intake: 1.6579-1.6618 in. (42.11-42.21 mm)
       
      Exhaust: 1.6520-1.6559 in. (41.96-42.06 mm)
       

    4.  
    5. Minimum cam lobe height:

      Intake: 1.6520 in. (41.96 mm)
       
      Exhaust: 1.6461 in. (41.81 mm)

      Click image to see an enlarged view

      Fig. Inspect cam lobe height

       

    6.  
    7. If the lobe height is less than minimum, replace the camshaft.
    8.  

  8.  
  9. Inspect the camshaft journals:
    1. Using a micrometer, measure the journal diameter. Journal diameter:

      Intake: 1.0610-1.0616 in. (26.949-26.965 mm)
       
      Exhaust: 1.0613-1.0620 in. (26.959-26.975 mm)

      Click image to see an enlarged view

      Fig. Inspect camshaft journal diameter

       

    2.  
    3. If the journal diameter is not as specified, check the oil clearance.
    4.  

  10.  
  11. Inspect the camshaft bearings:
    1. Check that bearings for flaking and scoring.
    2.  
    3. If the bearings are damaged, replace the bearing caps and cylinder head as a set.
    4.  

  12.  
  13. Inspect the camshaft journal oil clearance:
    1. Clean the bearing caps and camshaft journals.
    2.  
    3. Place the camshafts on the cylinder head.
    4.  
    5. Lay a strip of Plastigage across each of the camshaft journals.

      Click image to see an enlarged view

      Fig. Lay a strip of Plastigage across each of the camshaft journals

    6.  
    7. Install the bearing caps and tighten to 12 ft. lbs. (16 Nm).
      NOTE
      Do not turn the camshaft.

    8.  
    9. Remove the bearing caps.
    10.  
    11. Measure the Plastigage at its widest point.

      Standard oil clearance: 0.0014-0.0028 in. (0.035-0.072 mm)
       
      Maximum oil clearance: 0.0039 in. (0.10 mm)
       

    12.  
    13. If the oil clearance is greater than maximum, replace the camshaft. If necessary, replace the bearing caps and cylinder head as a set.
    14.  
    15. Completely remove the Plastigage.
    16.  
    17. Remove the camshafts.

      Click image to see an enlarged view

      Fig. Measure the Plastigage at its widest point

    18.  

  14.  
  15. Inspect camshaft thrust clearance:
    1. Install the camshafts.
    2.  
    3. Using a dial indicator, measure the thrust clearance while moving the camshaft back and forth.

      Standard thrust clearance: 0.0016-0.0035 in. (0.040-0.090 mm)
       
      Maximum thrust clearance: 0.0047 in. (0.12 mm)
       

    4.  
    5. If the thrust clearance is greater than maximum, replace the camshaft. If necessary, replace the bearing caps and cylinder head as a set.
    6.  
    7. Remove the camshafts.

      Click image to see an enlarged view

      Fig. Inspect camshaft thrust clearance

    8.  

  16.  
  17. Inspect the camshaft gear backlash:
    1. Install the camshafts without installing the exhaust cam sub-gear.
    2.  
    3. Using a dial indicator, measure the backlash.

      Standard backlash: 0.0008-0.0079 in. (0.020-0.200 mm)
       
      Maximum backlash: 0.0188 in. (0.30 mm)
       

    4.  
    5. If the backlash is greater then maximum, replace the camshafts.
    6.  
    7. Remove the camshafts.

      Click image to see an enlarged view

      Fig. Inspect the camshaft gear backlash

    8.  

  18.  
  19. Inspect the camshaft gear spring:
    1. Using vernier calipers, measure the free distance between the spring ends. Free distance: 0.712-0.740 in. (18.2-18.8 mm)
    2.  
    3. If the free distance is not as specified, replace the gear spring.

      Click image to see an enlarged view

      Fig. Inspect the camshaft gear spring

    4.  

  20.  

Removal & Installation



Specific to:

Toyota Avalon 1995-1996

  1. Before servicing the vehicle, refer to the Precautions Section.
  2.  
  3. Remove the timing belt and idler pulley.
  4.  
  5. Remove the camshaft timing pulleys.

    Click image to see an enlarged view

    Fig. View of the left cylinder head with exhaust (1) and intake (2) camshafts

  6.  
  7. Remove the cylinder head covers.
    NOTE
    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.



    Click image to see an enlarged view

    Fig. Place a service bolt in the camshaft sub-gear to secure it

  8.  
  9. 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 one mark each.)
    2.  
    3. Secure the exhaust camshaft sub-gear 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 sub-gear 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 eight 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 and then lift out the intake camshaft.

      Click image to see an enlarged view

      Fig. Right intake camshaft bearing cap bolt loosening sequence



      Click image to see an enlarged view

      Fig. Right side exhaust camshaft bearing cap bolt loosening sequence



      Click image to see an enlarged view

      Fig. Lift the caps and bolts up and place in order of removal-intake camshaft shown



      Click image to see an enlarged view

      Fig. All bearing caps are marked with an E or I

    10.  

  10.  
  11. 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 one mark each.)
    2.  
    3. Secure the exhaust camshaft sub-gear to the main gear using a service bolt. A bolt 0.63-0.79 inch (16-20mm) long with a 6mm thread diameter and a 1mm pitch is recommended. When removing the exhaust camshaft be sure the sub-gear 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 eight 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 reverse order of the installation sequence. Remove the bearing caps, keeping them in order, remove the oil seal and then lift out the intake camshaft.

      Click image to see an enlarged view

      Fig. Carefully lift the camshaft out and carry in the vertical position shown-intake camshaft shown



      Click image to see an enlarged view

      Fig. Left intake camshaft bearing cap bolt loosening sequence



      Click image to see an enlarged view

      Fig. Left side exhaust camshaft bearing cap bolt loosening sequence



      Click image to see an enlarged view

      Fig. Removing the left side exhaust camshaft

    10.  

  12.  
  13. Remove the valve lifter shims and hydraulic lifters. Identify each lifter and shim as it is removed so it can be reinstalled in the same position. If the lifters are to be reused, store them upside down in a sealed container.
  14.  

To install:

  1. Install the valve lifters into their original positions and install the shims. Check valve clearance and replace the shims as necessary.
  2.  
  3. When reinstalling, remember that the camshafts must be handled carefully and kept straight and level to avoid damage.

    Click image to see an enlarged view

    Fig. Right exhaust bearing caps must be placed in their proper locations



    Click image to see an enlarged view

    Fig. Right exhaust camshaft bearing cap bolt tightening sequence

  4.  
  5. Before installing the camshafts in either cylinder head, apply multi-purpose grease to each camshaft.
  6.  
  7. To install the right camshafts:
    1. Position the intake 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.
    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 " 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.

      Click image to see an enlarged view

      Fig. Use a torque wrench to tighten the cap bolts



      Click image to see an enlarged view

      Fig. Right intake bearing caps must be placed in their proper locations



      Click image to see an enlarged view

      Fig. Right intake camshaft bearing cap bolt tightening sequence

    12.  

  8.  
  9. 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.

      Click image to see an enlarged view

      Fig. Left exhaust bearing caps must be placed in their proper locations



      Click image to see an enlarged view

      Fig. Left exhaust camshaft bearing cap bolt tightening sequence



      Click image to see an enlarged view

      Fig. Left intake bearing caps must be placed in their proper locations



      Click image to see an enlarged view

      Fig. Left intake camshaft bearing cap bolt tightening sequence

    12.  

  10.  
  11. Apply multi-purpose grease to new camshaft oil seals. Install the seals.

    Click image to see an enlarged view

    Fig. The camshaft seals are on the end of the component

  12.  
  13. Install the No. 3 (rear) timing belt cover.
  14.  
  15. Install the camshaft timing gears.
  16.  
  17. Install the idler pulley, timing belt and covers.
  18.  
  19. Check and adjust the valve clearance.
  20.  
  21. Install the cylinder head (valve) covers.
  22.  
  23. Start the engine. Check the ignition timing.
  24.  
  25. Test drive the vehicle.
  26.  
  27. Check all fluid levels.
  28.  

 
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