GM Service Manual Online
For 1990-2009 cars only

Removal Procedure

    Caution: Unless directed otherwise, the ignition and start switch must be in the OFF or LOCK position, and all electrical loads must be OFF before servicing any electrical component. Disconnect the negative battery cable to prevent an electrical spark should a tool or equipment come in contact with an exposed electrical terminal. Failure to follow these precautions may result in personal injury and/or damage to the vehicle or its components.

  1. Disconnect the negative battery cable.
  2. Remove the crankshaft pulley. Refer to Crankshaft Pulley Replacement .

  3. Object Number: 166284  Size: SH
  4. Disconnect the wiring harness conduit from the timing belt cover (8).
  5. Remove the following from the engine:
  6. • Eight timing belt cover bolts
    • One timing belt cover nut
    • The timing belt cover (8)

    Important: There are two sets of timing marks which must be aligned in order to ensure correct engine timing belt installation. A mark on the camshaft timing belt gear designated as E must be aligned with the notch on the cylinder head cover. The mark on the crankshaft timing belt gear should also be aligned with the arrow on the oil pump housing. Ensure alignment of both sets of marks prior removing the timing belt to ensure correct timing belt installation and engine timing.


    Object Number: 166291  Size: SH
  7. Ensure the alignment of the lower timing marks on the oil pump housing (2) and the crankshaft timing belt gear (1). If the timing marks are not aligned, rotate the crankshaft clockwise until the timing marks are aligned.

  8. Object Number: 166290  Size: SH
  9. Note the position of the upper timing marks (1,2). If the upper timing marks are not aligned as illustrated, rotate the crankshaft clockwise one revolution until the upper and lower timing marks are properly aligned .

  10. Object Number: 166292  Size: SH
  11. Loosen the timing belt tensioner bolt (4).
  12. Remove the timing belt tensioner spring from the timing belt tensioner plate (1).
  13. Remove the timing belt from the camshaft and the crankshaft timing belt gears.
  14. Notice: Do not turn the crankshaft and camshaft independently of one another once the timing belt has been removed. If the crankshaft or camshaft is turned independently, interference between the pistons and valves may occur causing component damage.

  15. Inspect the timing belt tensioner for smooth operation. Replace the timing belt tensioner if necessary. Refer to Timing Belt Tensioner Replacement .

Installation Procedure

Notice: When installing a new or used timing belt, the directional arrows on the timing belt must be matched with the rotation of the crankshaft. If this precaution is not observed, excessive wear and timing belt failure may occur.

Important: Do not tighten the timing belt tensioner stud and bolt to specification until the timing belt is properly installed. Install the timing belt tensioner stud and bolt finger tight only.


    Object Number: 262564  Size: SH
  1. Push the timing belt tensioner plate (1) up for the timing belt installation.

  2. Object Number: 262569  Size: SH
  3. Install the timing belt (1) onto the camshaft and the crankshaft timing belt gears.
  4. Inspect the timing marks on the cylinder head cover and the camshaft timing belt gear for alignment as well as the timing marks on the oil pump housing and the crankshaft timing belt gear. If these two sets of timing marks are not properly aligned, remove the timing belt and align both sets of marks as previously outlined in this procedure.

  5. Object Number: 166292  Size: SH
  6. Install the timing belt tensioner spring to the timing belt tensioner plate (1).
  7. Rotate the crankshaft two complete revolutions to remove any slack from the timing belt and to properly seat the timing belt.
  8. Notice: Use the correct fastener in the correct location. Replacement fasteners must be the correct part number for that application. Fasteners requiring replacement or fasteners requiring the use of thread locking compound or sealant are identified in the service procedure. Do not use paints, lubricants, or corrosion inhibitors on fasteners or fastener joint surfaces unless specified. These coatings affect fastener torque and joint clamping force and may damage the fastener. Use the correct tightening sequence and specifications when installing fasteners in order to avoid damage to parts and systems.

    Important:  When all of the slack has been removed from the timing belt, inspect both sets of the timing marks to ensure that they are properly aligned . If the timing marks are not aligned, remove the timing belt and align both sets of marks as previously outlined in this procedure.

  9. After the timing belt has been rotated and seated, tighten the timing belt tensioner stud.
  10. Tighten
    Tighten the timing belt tensioner stud to 11 N·m (97 lb in).

  11. Install the timing belt tensioner bolt.
  12. Tighten
    Tighten the timing belt tensioner bolt to 27 N·m (20 lb ft).

  13. Install the timing belt cover to the engine. Secure the cover with one nut and eight bolts.
  14. Tighten
    Tighten the timing belt cover nut and bolts to 10 N·m (89 lb in).

  15. Connect the wiring harness conduit to the timing belt cover.
  16. Install the crankshaft pulley. Refer to Crankshaft Pulley Replacement .
  17. Connect the negative battery cable.
  18. Tighten
    Tighten the battery cable to 15 N·m (11 lb ft).