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Old 03-01-2004, 07:45 AM   #1
Morphias87
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Heres another for you guys.

Short and simple,what exactly is overdrive?
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Old 03-01-2004, 07:59 AM   #2
BavarianWheels
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Quote:
Originally Posted by Morphias87
Short and simple,what exactly is overdrive?

It's like a "5th gear" in an automatic. There's usually a button on the gear selector and a light that comes on if OD is off.

Normally used around town, but off if going to do some "mountain" driving.

That's my take on it...I'm sure there will be better and more technical explanations coming.
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Old 03-01-2004, 01:26 PM   #3
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Quote:
Originally Posted by Morphias87
Short and simple,what exactly is overdrive?
Basically, in the olden days, top gear in a transmission was direct drive which is a 1:1 ratio. Early overdrives were a seperate bolt-on unit using a planetary gearset that when engaged raised the ratio beyond 1:1, that of course lowered engine speed for any given road speed. Overdrive units of this type can still be bought new from a company called Gear Vendors.

Modern overdrive transmissions/transaxles accomplish the same thing in a different way. Most of them are 5 or 6 speeds where 4th gear is the direct drive. The higher gears have overdrive ratios built right in. This saves a certain amount of weight and complexity but accomplishes the same thing.
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Old 03-02-2004, 05:35 AM   #4
Morphias87
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Thnx guys!
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