Midori Green

can somebody explain what this is and what it has to do with gearing?? i cant find the definition of it on answers.com or dictionary.com

AnotherSI

final drive is the ratio between the speed of the intermediate shaft or differential drive pinion and the ring gear on the differential assembly. alot of people refer to final drive as top gear(5th for most of us). which is mostly incorrect. each gear has its own ratio ie 10:1...every 10 input revolutions produce 1 output revolution. this ratio is again reduced by the differential assmebly. so 1st gears ratio is going to be different than 2nd gear obviously but how much the the differential reduces the ratio is going to be the same for every gear. kinda hard to put into words... try howstuffworks.com. pictures are always nice.