By Jeff Glucker
There are strong gearboxes, and then there’s the Lenco. You’ve seen one before, most likely, but also probably wondered what the hell it is that you’re staring at. Multiple shift levers? How does this thing work and also…why? Well, I found a video that does a great job explaining what a Lenco is, how it works, and why it’s useful for high-horsepower machines.
A Lenco gearbox uses planetary gears in an interesting way that allows an essentially two-speed gearbox to become much more. You have a sun gear and a planetary gear in a housing, with each delivering a set gear ratio. Then you had multiple housings with more gear sets, thus adding more gear ratios.
The setup’s popularity is that, despite its strange appearance, it’s actually simple once you understand what’s happening inside the case. And it also happens to be extremely strong. This is why it’s a favorite for drag racers running tremendous power. When you dump the clutch on a car with serious torque, the Lenco goes “Oh, sweet!” where a standard gearbox might go “AAAAHHHHHH I’m going to explode!”
Watch the video above for a better, smarter, and more in-depth explanation than I’ve delivered here. It provides a great look at what’s happening inside the crazy-looking transmission with all the levers.
Robert Crespo 
Kamil Kaluski