<VV> manual transmission lube - trivia

[NicolCS@aol.com]

Idle minds...
The discussion about EP (Extreme pressure) requirements for Corvair 
differential oil got me to thinking.  Just what does "hypoid" mean?  I recoginzed the 
"poid" root as meaning roughly "weight".  Was "hypoid" a coined word or 
trademark term?  Hypoid =high-weight=extreme pressure?  A little dictionairy work 
yielded:

hypoid gear
noun  a gear having a tooth form generated by a hypocycloidal curve; used 
extensively in motor vehicle transmissions to withstand a high surface loading
[ETYMOLOGY: 20th Century: hypoid, shortened from hypocycloid    

hypocycloid
noun  a curve described by a point on the circumference of a circle as the 
circle rolls around the inside of a fixed coplanar circle

Now you know (oh swell!)
Craig (knower of useless things) Nicol