GM Service Manual Online
For 1990-2009 cars only

Tools Required

SA9181NE Belt Tension Gage

Belt and Tensioner Load Inspection


    Object Number: 894682  Size: SH
  1. The following procedure is to be used when the belt or tensioner is suspected of allowing pulleys to slip or causing any unusual belt noises.
  2. 1.1. Warm up the engine for approximately 10 minutes with all accessories turned ON.
    1.2. The steering wheel must be turned full left and right several times, if equipped with power steering.

    Object Number: 894336  Size: SH
  3. Shut the engine OFF.
  4. Using a 15 mm wrench, rotate the tensioner arm clockwise until the belt becomes loose on the pulleys. Slowly allow the tensioner to apply tension back on the belt.

  5. Object Number: 896414  Size: SH

    Important: The marking on the tensioner arm must fall within the operating range (2 marks) on the tensioner body. If the tensioner marks fall outside the operating range, the accessory drive belt must be replaced.

  6. The tensioner pulley must not be allowed to snap against the belt.

  7. Object Number: 894686  Size: SH
  8. Using a calibrated SA9181NE , or equivalent, (OTC® OEM 1294), read and record the belt tension at mid span for the following drive combinations. This check can be performed on an engine assembly removed from the vehicle. It can not be performed with the engine in the vehicle unless the upper engine mount is removed.
  9. Repeat steps 2 and 5 three times and record the information.

  10. Object Number: 888348  Size: SH
  11. Add the 3 readings together and divide the total by 3 , as shown in the example:
  12. • Belt Tension = Readings / (# of readings)
    • Belt Tension = [(1)+(2)+(3)] / 3
    • Example: (54 + 58 + 52) = 164 / 3
    • Belt Tension = 55 lb.
  13. Refer the belt tension chart for specifications.

Accessory Drive Belt Inspection


    Object Number: 873081  Size: MH
  1. Minor cracks in the belt rib are normal. They are the result of reverse bending around a backside pulley. Do not replace belts for minor cracks.
  2. Belts that have chunking longer than 5 mm (13/16 in) in one or more places should be replaced.


    Object Number: 873083  Size: SH
  3. Belts should also be replaced if cord breakage or fabric separation is observed.