Service, Operator & Repair manuals are available for most tractors:
(some lawn mowers, heavy equipment and implements, too):
1) Service (Repair) - detailed disassembly, repair, and re-assembly.
2) I & T Service - "For the experienced mechanic" Very condensed..
3) Parts - Detailed diagrams of parts, part name & OEM part no.
4) Operators - Operation, general maintenance, specifications, etc.