How automatic gearboxes work

[GazHyde]

Just found a couple of interesting videos about gearboxes and torque converters. I'm not sure how relevant they are to BMW gearboxes, perhaps someone can comment who knows what they are on about!

The first video explains the principals of automatic transmissions that use a Ravingneaux planetary gear set (means absolutely nothing to me!)

View: http://youtu.be/Y1zbE21Pzl0


The second video explains the theories behind a torque converter...

View: http://youtu.be/z5G2zQ_3xTc

 

[Cooper]

@GazHyde I have an automatic step-tronic and love it. It seems really strong and when I place Brandy in park she 'sits down'. Nice beemer, sit, good beemer! 'Quote from Jim Carey in Fun with Dick and Jane. Anyway, when going down a hill at speed the gearbox will grab the engine and use it to slow you down if you tough the brakes, which I hate, so I flick it over into step-tronic and up the gears manually one or two, relieving the backwards pressure and keeping the speed up! Thought I would throw that in there for other members that may not have used that approach. Cooper