Fits 2001 Freightliner FL80. 2001 Freightliner FL80 Engine: 8.3L L6 DIESEL; Position: Fan and Alternator;. Part Type: Accessory Drive Belt Tensioner Assembly. HD TENSIONER. Belt Type: Serpentine. To confirm that this part fits your vehicle, enter your vehicle's Year, Make, Model, Trim and Engine in theCompatibility Table.