Wiktionary
three-on-the-tree
alt. (context US idiomatic English) On an automobile (especially those produced from 1939 through the mid-1970s), a three-speed manual transmission whose gearshift lever is mounted on the steering column. n. (context US idiomatic English) On an automobile (especially those produced from 1939 through the mid-1970s), a three-speed manual transmission whose gearshift lever is mounted on the steering column.