Ford transmission diagrams show repair experts where certain components are located. While diagrams can show both manual and automatic transmissions, manual transmissions are generally simpler, and many repair experts don't need a diagram to inspect a system.
The core component of an automatic transmissions is the planetary gear configuration, which uses several gears. Automatic transmissions use hydraulic fluid to ensure smooth gear changes and to provide power to the system. Newer automatic transmissions also lock into place to prevent the slippage that caused older automatic systems to operate inefficiently. This complexity, combined with the self-contained nature of automatic transmissions, means that even seasoned experts might need guidance when looking at an unfamiliar system.