Belt And TENSIONER Load Inspection

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.

Fig 1: Drive Belt Routing

Courtesy of GENERAL MOTORS CORP.

1. Warm up the engine for approximately 10 minutes with all accessories turned on. The steering wheel must be turned full left and right several times, if equipped with power steering.
2. Shut the engine off.
   NOTE: A Snap-on® tool S8190A (or equivalent) wrench can be used to easily access the tensioner release bolt.
3. Using a 14 mm or 9/16 in. wrench, depress the tensioner arm until the belt becomes loose on the pulleys. Slowly allow the tensioner to apply tension back on the belt.
   Fig 2: Un-tensioning Belt

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   NOTE: The marking on the tensioner arm must fall within the operating range (two marks) on the tensioner body. If the tensioner marks fall outside the operating range, the accessory drive belt must be replaced.
   NOTE: The tensioner pulley must not be allowed to snap against the belt.
   Fig 3: Belt Tensioner

   Courtesy of GENERAL MOTORS CORP.
4. Using Calibrated Belt Tension Gauge SA9181NE (or equivalent) (OTC® OEM 1294 or equivalent), 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 cannot be performed with the engine in the vehicle unless the upper engine mount is removed.
5. Repeat the previous steps three times and record the information.
   Fig 4: Read And Record The Belt Tension

   Courtesy of GENERAL MOTORS CORP.
6. Add the three readings together and divide the total by three as shown in the example:

   Readings: 

   Belt Tension =  (1) + (2) + (3) / 3 (# of readings)

   Example:  54 + 58 + 52 = 164/3

   Belt Tension =  55 lbs.

7. Refer to belt tension chart for specifications.
   Fig 5: Belt Tension Chart

   Courtesy of GENERAL MOTORS CORP.