Most transmissions in modern vehicles use synchromesh to synchronise the speeds on the enter and output shafts. Having said that, prior to the 1950s, most cars used non-synchronous transmissions. An computerized transmission would not demand any enter from the driving force to alter ahead gears underneath normal driving problems. https://gearbox22974.blogdeazar.com/33958253/how-much-you-need-to-expect-you-ll-pay-for-a-good-gearbox