Drive Belt: Adjustments

Belt Tensioner:

Serpentine Belt Tensioner:

WARNING: To avoid personal injury when rotating the serpentine belt tensioner, use a tight fitting 13 mm wrench that is at least 61 cm (24") long.


1. Inspect tensioner markings to see if the belt is within operating lengths. Replace belt if the belt is excessively worn or is outside of the tensioner's operating range.
2. Run the engine with no accessories on until the engine is warmed up. Shut the engine off and read belt tension with J 36018 placed halfway between the generator and the A/C compressor (or idler pulley for non A/C applications), Remove tool.

NOTE: This operation can be done using Tool J 37059 or equivalent.

3. Start the engine (with accessories off) and allow the system to stabilize for 15 seconds. Turn the engine off. Using a 13 mm box end wrench, apply clockwise force (tighten) to the tensioner pulley bolt. Release the force and immediately take a tension reading without disturbing belt tensioner position.
4. Using the same wrench, apply a counterclockwise force to the tensioner pulley bolt and raise the pulley to the "install" position. Slowly lower the pulley to the "at rest" position and take a tension reading without disturbing the belt tensioner position.
5. Average the three readings. If the average of the three readings is lower than 68Nm (50 lbs. ft.) and the belt is within the tensioner's operating range, replace the tensioner bracket assembly.