gear shift vs gearbox

gear shift

noun
  • That part of a gearbox involved in changing gear, including the lever and the forks attached to it. 

  • The lever or other interface a human uses to shift gears. 

gearbox

noun
  • That part of a car's transmission containing the train of gears, and to which the gear lever is connected. 

  • An enclosed gear train. 

How often have the words gear shift and gearbox occurred in a corpus of books? (source: Google Ngram Viewer )