A guide on how to change the three oil compartments on the Harley Davidson Twin Cam motorcycle. Also cleaning or replacing the air filter and spark plugs with very important engine longevity advice and implementing the author's perpetual oil change procedure to increase engine longevity. This book can also be used, with minor procedural adjustments, to change the oil on Big Twin, Dyna, Electraglide, Softail, Sportster, Buell and all other early and late models of Harley Davidson V-twin engines except the V-rod. This book has been written specifically for the beginning mechanic who needs to learn how to change the oil in V-Twin Harley Davidson motorcycles and especially the Twin-cam engine. 141 pages of detailed step-by-step instructions with 80 photographs make it very easy to learn.