Hard parts are the toughest and most durable components. For example, these are parts that have become damaged or broken and need to be replaced in order for the transmission to function within OEM standards. Such “Hard Parts” include the following: the rear sun, rear planet gear, clutch drums, gears, pump assembly, clutch hub, pump rotor, etc.
Depending upon the type of vehicle, such parts cost anywhere from $25 up to $300. The hard parts are more durable. Hence they have a longer life, than do the soft parts.