GM Service Manual Online
For 1990-2009 cars only

Tools Required

J 7872 Magnetic Base Dial Indicator


    Object Number: 60261  Size: SH
  1. Mount the J 7872 to the front of the block.
  2. Position the dial indicator so that the plunger contacts the timing chain between the two sprockets.
  3. Pull the chain outward, parallel to the front face of the block, to the maximum amount, with finger pressure on the inside of the chain.
  4. Set the J 7872 to zero.
  5. Move the chain inward, parallel to the front face of the block, to the maximum amount with finger pressure on the outside of the chain.
  6. Note the total indicator travel.
  7. • With used parts, the deflection must not exceed 20.3 mm (0.80 in).
    • If the deflection exceeds this limit, inspect the sprockets and the timing chain for wear and replace the worn parts.
    • With new parts, the deflection must not exceed 12.7 mm (0.50 in).