When servicing the vacuum pump, the pulley is serviced separately. To install the pulley, GM-49756 is used to ensure the pulley is positioned correctly and flush with the end of the pump shaft. The nut and bolt from GM-49756 are assembled through the included thrust bearing and spacer. This assembly is inserted through the pulley (with the spacer contacting the pulley) and threaded into the end of the pump shaft. The bolt is held, and the nut tightened against the thrust bearing to seat the pulley to the end of the pump shaft. Using unapproved methods can damage the pump or cause belt misalignment.