power train vs gearing

power train and gearing both are nouns.

Word	Noun	Adjective	Verb	Adverb
power train	Yes	No	No	No
gearing	Yes	No	No	No

As nouns, power train and gearing are synonyms defined as:

power train and gearing: wheelwork consisting of a connected set of rotating gears by which force is transmitted or motion or torque is changed

Other synonyms of power train include gear, geartrain, train.

power train (noun)	gearing (noun)
wheelwork consisting of a connected set of rotating gears by which force is transmitted or motion or torque is changed	wheelwork consisting of a connected set of rotating gears by which force is transmitted or motion or torque is changed