gearbox vs standard transmission

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. 

standard transmission

noun
  • Mechanical transmission which shifts gears by the action of the driver's hand on the gearstick or gear lever, rather than automatically; a manual gearbox. 

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