This variable speed belt drives the alternator from the engine crankshaft, using a toothed inner profile to maintain positive engagement across a range of pulley diameters. It sits in the accessory drive system, where the belt's variable-speed capability allows the alternator output to remain stable as engine RPM changes. A worn belt slips under load, causing the alternator to undercharge the battery and triggering a warning lamp. Gates manufactures this belt to match the original tooth profile and pitch, ensuring it seats correctly in the pulleys without noise or vibration. On installation, verify the belt tensioner operates within its travel range and that the belt tracks centered on all pulleys.