Most transmissions in modern cars and trucks use synchromesh to synchronise the speeds of the input and output shafts. Having said that, prior to the fifties, most cars and trucks employed non-synchronous transmissions. Torque converter does precisely the same operate that the clutch does within the handbook gearbox process. https://gearbox08529.jts-blog.com/32796828/top-guidelines-of-gearbox