Lexus GS, SC 1998-06

Timing Belt & Sprockets

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Removal & Installation



1uz-FE & 3uz-FE Engines


Click image to see an enlarged view

Fig. Exploded view of the timing belt and cover assembly and related components-4.3L (3UZ-FE) Engine

  1. Remove all necessary components for access to the right-hand side No. 3 and No. 2, and left-hand side No. 2 timing belt covers, then remove the covers.
  2.  
  3. Turn the crankshaft pulley and align it's groove with the timing mark 0 of the No. 1 timing cover. Check that the timing marks of the camshaft timing pulleys and timing belt rear plates are aligned. If not, turn the crankshaft 1 full revolution (360°).
  4.  
  5. Loosen crankshaft pulley bolt, then set the No. 1 cylinder to about 50°ATDC on the compression stroke. With the crankshaft pulley notch aligned with the 0 mark on the timing belt cover, turn the crankshaft pulley about 50°clockwise and put timing mark of the crank pulley in line with the centers of the pulley bolt and the No. 2 timing belt idler pulley bolt.
  6.  
  7. Remove or disconnect the following, as applicable for the vehicle:
    NOTE
    If the timing belt is to be reused, draw a directional arrow on the timing belt in the direction of engine rotation (clockwise) and place matchmarks on the timing belt and crankshaft gear to match the drilled mark on the pulley.



    Timing belt tensioner. Using the proper tool, loosen the tension between the left side and right side timing pulleys by slightly turning the left side camshaft clockwise.
     
    Timing belt from the camshaft timing pulleys
     
    Power steering pump pulley
     
    Alternator
     
    Drive belt tensioner
     
    Bolt and timing pulleys, using the proper tool
     
    Bolt and the crankshaft pulley with the proper tool.
     
    Fan bracket
     
    Mounting bolts and the No. 1 timing belt cover
     
    2 upper and lower timing belt covers
     
    Timing belt guide (No. 1 crank position sensor plate)
     
    Timing belt
     
    No. 1 and No. 2 timing belt idler pulleys, if necessary.
     



    Click image to see an enlarged view

    Fig. Timing belt sprocket mark alignment for belt installation-Lexus 4.0L (1UZ-FE) engine



    Click image to see an enlarged view

    Fig. Timing belt sprocket mark alignment for belt installation-4.3L (3UZ-FE) Engine

  8.  

To install:

  1. Align the installation mark on the timing belt with the drilled mark of the crankshaft timing pulley. Install the timing belt on the crankshaft timing pulley, No. 1 idler pulley and the No. 2 idler pulley.
    NOTE
    If the old timing belt is being reinstalled, be sure the directional arrow is facing in the original direction and that the belt and crankshaft gear matchmarks are properly aligned.

  2.  
  3. Install the timing belt guide (No. 1 crank angle sensor plate) with the cup side facing forward. Replace the timing belt cover spacer.
  4.  
  5. Install the No. 1 timing belt cover and tighten the mounting bolts.
  6.  
  7. Align the pulley set key on the crankshaft with the key groove of the pulley. Install the pulley, using the proper tool to tap in the pulley. Tighten the pulley bolt to 181 ft. lbs. (245 Nm).
  8.  
  9. Align the knock pin on the right side camshaft with the knock pin of the timing pulley. Slide on the timing pulley with the right side mark facing forward. Tighten the bolt to 80 ft. lbs. (108 Nm).
  10.  
  11. Align the knock pin on the left side camshaft with the knock pin of the timing pulley. Slide on the timing pulley with the left side mark facing forward. Tighten the bolt to 80 ft. lbs. (108 Nm).
  12.  
  13. Turn the crankshaft pulley and align its groove with the 0 timing mark on the No. 1 timing belt cover. Using the proper tool, turn the crankshaft timing pulley and align the timing marks of the camshaft timing pulley and the timing belt rear plate.
  14.  
  15. Install the timing belt to the left side camshaft timing pulley by:
    1. Using the proper tool, slightly turn the left side timing pulley clockwise. Align the installation mark of the timing belt with the timing mark of the camshaft timing pulley and hang the timing belt on the left side camshaft pulley.
    2.  
    3. Using the proper tool, align the timing marks of the left side camshaft pulley and the timing belt rear plate.
    4.  
    5. Check that the timing belt has tension between crankshaft timing pulley and the left side camshaft pulley.
    6.  

  16.  
  17. Install the timing belt to the right side camshaft timing pulley by:
    1. Using the proper tool, slightly turn the right side timing pulley clockwise. Align the installation mark of the timing belt with the timing mark of the camshaft timing pulley and hang the timing belt on the right side camshaft pulley.
    2.  
    3. Using the proper tool, align the timing marks of the right side camshaft pulley and the timing belt rear plate.
    4.  
    5. Check that the timing belt has tension between the crankshaft timing pulley and the right side camshaft pulley.
    6.  

  18.  
  19. The timing belt tensioner must be set prior to installation. The tensioner can be set as follows:
    1. Place a plate washer between the tensioner and a block. Using a suitable press, press in the pushrod using 220-2205 lbs. (100-1000kg) of pressure.
    2.  
    3. Align the holes of the pushrod and housing, pass the proper tool (0.05 in. Allen wrench) through the holes to keep the setting position of the pushrod.
    4.  
    5. Release the press and install the dust boot on the tensioner.
    6.  

  20.  
  21. Install the tensioner and tighten the bolts to 20 ft. lbs. (26 Nm). Remove the tool from the tensioner.
  22.  
  23. Turn the crankshaft pulley two complete revolutions from TDC-to-TDC. Always turn the crankshaft clockwise. Check that each pulley aligns with the timing marks.
  24.  
  25. Install all remaining components in the reverse order of removal.
  26.  

2jz-Ge Engine
  1. Before servicing the vehicle, refer to the Precautions section.
  2.  
  3. Remove all necessary components for access to the upper timing belt covers. Using a 5mm Allen wrench, remove the 9 bolts and lift off the two upper (No. 2 and No. 3) timing belt covers.
  4.  
  5. Rotate the crankshaft pulley clockwise so its groove is aligned with the 0 mark in the No. 1 (lower) timing cover. Check that the timing marks on the camshaft timing sprockets are aligned with the marks on the No. 4 (inner) cover. If not, rotate the crankshaft 1 complete revolution (360 degrees).
  6.  
  7. Alternately loosen the 2 tensioner mounting bolts and remove them, the tensioner and the dust boot. Slide the timing belt off of the 2 camshaft sprockets. Its a good idea to matchmark the belt to the pulleys.
  8.  
  9. Ensuring the timing belt is securely supported, hold the crankshaft pulley with a spanner wrench and loosen the mounting bolt. Remove the bolt and the pulley.
  10.  
  11. Remove or disconnect the following:
    NOTE
    If the timing belt is to be reused, draw a directional arrow on the timing belt in the direction of engine rotation (clockwise) and place matchmarks on the timing belt and crankshaft gear to match the drilled mark on the pulley.



    5 bolts, then lift off the lower No. 1 timing belt cover
     
    Timing belt guide
     
    Timing belt
     



    Click image to see an enlarged view

    Fig. Set the engine to TDC by aligning the marks before removing the lower timing cover-Lexus 3.0L (2JZ-GE) engine

  12.  

To install:

  1. Install the timing belt on the crankshaft timing pulley and the idler pulleys.
    NOTE
    If the old timing belt is being reinstalled, be sure the directional arrow is facing in the original direction and that the belt and crankshaft gear matchmarks are properly aligned.

  2.  
  3. Install the timing belt guide. Install the lower (No. 1) timing cover and tighten the bolts.
  4.  
  5. Align the crankshaft pulley set key with the key groove on the pulley and slide the pulley on. Tighten the bolt to 239 ft. lbs. (324 Nm).
  6.  
  7. Set the No. 1 cylinder to TDC again. Turn the camshaft until the sprocket timing marks are aligned with the timing marks on the No. 4 belt cover.
  8.  
  9. Check that the marks on the belt matches with those on the sprockets, then slide it over the sprockets. If not, shift it on the crank pulley until it does.
  10.  
  11. Position a plate washer between the timing belt tensioner and the block, then press in the pushrod until the holes are aligned between it and the housing. Slide a 1.5mm Allen wrench through the hole to keep the pushrod set. Install the dust boot, then install the tensioner. Tighten the bolts to 20 ft. lbs. (26 Nm). Don't forget to pull out the Allen wrench.
  12.  
  13. Turn the crankshaft clockwise two complete revolutions and check that all marks are still in alignment. If they aren't, remove the timing belt and start over again.
  14.  
  15. Position new gaskets, then install the upper (No. 2 and No. 3) timing covers.
  16.  

 
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