1998 Mack RB Engine: 11.9L -6 DIESEL; Position: Fan and Alternator;. 1999 Mack RB Engine: 11.9L -6 DIESEL; Position: Fan and Alternator;. 2000 Mack RB Engine: 11.9L -6 DIESEL; Position: Alternator;. Part Type: Accessory Drive Belt Tensioner Assembly.
