The appropriate repair depends on what has failed and the condition of the remaining components. An external leak may require a focused repair, while worn gears or bearings may call for internal work or replacement of an assembly.
A rebuild can involve replacing damaged components and carefully setting bearing preload, gear backlash, and contact pattern. In other cases, a replacement assembly may be a more practical option.
Certified Transmission at 527 SW State Route 7 Highway in Blue Springs can explain the findings, available parts, repair scope, and applicable warranty so you can compare the options for your vehicle.