Located on the front of the motor in your 2003-2006 Nissan 350Z (Z33) or Infiniti G35 (V35) this belt tensioner / idler pulley provides the belt a smooth surface to spin across while providing the proper amount of tension. As the bearings in the pulley wear, you may begin to experience a high pitch squeaking or squealing. Over time this may result in complete bearing failure, causing the pulley to lock up and break the belt. Improper installation also generally results in bent tensioner bolts, preventing you from achieving proper belt tension.

There are two separate belt tensioners on your VQ35DE. This listing is for the A/C belt tensioner pulley assembly. Accessory (alternator) pulley assemblies can be found HERE.