ISM, ISMe, and QSM11 – 008-030   Fan Drive Idler Pulley Assembly

Remove the fan drive belt. Refer to Procedure 008-002 in Section 8..

Inspect the idler pulley for:

• Freedom of rotation
• Cracked, chipped, or broken pulley grooves.

Measure the idler pulley end clearance.

Idler Pulley End Clearance

Replace or rebuild the idler pulley if the end clearance is not within these specifications. Refer to the Shop Manual, M11 Series Engines, Bulletin 3666075, for rebuilding procedures, or contact the local Cummins® Authorized Repair Location.

NOTE: For fan hub installations that were not manufactured by Cummins Inc., contact the OEM.

Loosen the fan idler pulley shaft locknut.

Loosen the adjusting mechanism and move the fan idler pulley and fan pulley centers as close as possible.

Remove the fan belt.

Remove the roll pin and washer from the idler pulley adjusting screw.

Remove the locknut and washer from the back of the idler pulley shaft.

Remove the adjusting screw.

Remove the fan idler pulley from the fan hub support bracket.

Inspect the idler pulley for:

• Freedom of rotation
• Cracked, chipped, or broken pulley grooves.

NOTE: Do not tighten the locknut until the fan drive belt has been installed and adjusted.

Install the idler pulley in the fan hub support bracket.

Install the washer and locknut on the idler pulley shaft.

Install the adjusting screw in the idler pulley shaft.

Turn the adjusting screw in far enough to install the washer and roll pin in the shaft at the bottom of the fan hub support bracket.

Install and adjust the fan drive belt. Refer to Procedure 008-002 in Section 8.

Refer to Procedure 018-005 in Section V for proper belt tension value.

Tighten the idler pulley shaft locknut.

Check the belt tension again after the locknut is tightened.