GM Service Manual Online
For 1990-2009 cars only

Tools Required

J 23600-B Belt Tension Gauge

  1. Run the engine, with no accessories on, until the engine is warmed up. Shut the engine off. Read the belt tension using J 23600-B placed halfway between the generator and the power steering pump. For Vehicles equipped with a supercharger, check the belt tension between the supercharger and the idler pulley. Note the reading and remove J 23600-B .
  2. Start the engine with the accessories off and allow the system to stabilize for 15 seconds. Turn the engine off. Using a 15-mm socket, apply clockwise force (tighten) to the tensioner pulley bolt. Release the force and immediately take a tension reading without disturbing belt tensioner position.
  3. Using the same wrench, apply a counterclockwise force to the tensioner pulley bolt and raise the pulley to eliminate all tension. Slowly lower the pulley to the belt and take a tensioner reading without disturbing the belt tensioner position.
  4. Average the three readings. If the average of the three readings is not between 133-222 N (30-50 lb) and the bolt is within the tensioners operating range, replace the tensioner.