This Oliver 550 Factory Parts Manual has exploded views of all parts on the Oliver 550 tractor. This book contains a complete listing of all parts released for repairs up to issue date for all regular production Model 550 gasoline or diesel tractors from serial number 60 501. A Table of Contents and an Alphabetical Index immediately follow this page, and a Details of Assembly and part number Numerical Index are listed in the back of the book. The book is divided into twelve numbered sections (See Table of Contents, Page II.) Each section is subdivided into smaller groups or units to simplify listing of parts and illustration by “exploded view”. Pages are numbered on the lower outer comer with the section number and page number within the section (2-1, 7-20, 10-17 etc.) The parts shown in “exploded views” of assemblies are. reference numbered and correspond to numbers in the Reference Number (Ref. No.) column of the parts list immediately following each illustration. When more than one identical part appears in an exploded view, usually only one will be reference numbered. DO NOT ORDER PARTS BY REFERENCE NUMBER. Hardware parts are listed immediately under the parts with which they are used. The total number of parts required per tractor, or per unit, is shown opposite each part number. Part numbers from various types of part numbering systems are included in this book. Be sure all numerals, prefix letters and/or suffix letters are included when listing parts. Part numbers (other than hardware) which have the letter “S” as part of the prefix or suffix indicate an assembly of parts (examples: 1KSA-2207-C, 104 622-ASA). When ordering repairs, the part number, descriptive name and quantity desired of each part ordered should be given. If it can be obtained, the tractor serial number should also be given. When ordering repairs for assemblies which have model numbers or serial numbers (examples: engines, carburetors, power steering gears), the model and/or serial numbers should be given.