What is a "bull gear"?

If you don't know, don't feel bad. I get asked the question so much that I felt the question deserves to be answered here...

You rarely hear the term these days, but I'll wager that if you mention it around an old-timer that has been around trucks, tractors and machinery, they'll know exactly what you're talking about. The term was originally used to describe the massive, slow, and powerful final drive gear used in large machinery. An example is shown below... (b) being the bull gear, driven by the pinion (a). 

How does this relate to our corporation? You'll occasionally here the term "bull gear" used interchangeably with the term "granny gear" when describing the low first gear ratio in some trucks and/or the main drive gear of a transfer case. It gives you the ability to slowly crawl over obstacles with seemingly unstoppable torque. It also relates to the powerful and agressive nature of the animal itself. Lastly, we've been known to have a  bull session or two about gears, being the born and bred gear heads that we are.

There ya have it... another useless bit of trivia to impress your friends. Just don't try to impress your girl by telling her how big your "bull gear" is. Chances are, she won't buy it.