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 and read the belt tension using the J 23600-B placed halfway between the generator and the power steering pump. For Vehicles equipped with supercharger check the belt tension between the supercharger and the idler pulley. Not the reading and remove the 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 225-315 N (50-70 lb) and the bolt is within the tensioners operating range, replace the tensioner.