www.jeeptech.com/javaAps/trans.txt

Part of content: Gear and Tire Applet User Guide: Transmissions

The Gear and Tire Applet allows you to enter up to 5 speeds and a reverse
gear ratio. If you have a 3 speed or don't have the reverse ratio, there is
no need to input the extra information. If you aren't sure what
transmission you have you can use the generalizations here to get numbers
that probably will be very accurate give or take a few KPH/MPH.

Generalizations About Manual Transmissions

Ratios for manual transmissions don't vary all that much. Most of the time
first gear is around 4:1 unless it granny low truck transmission such as
the T-18, NP435, SM465, SM420 etc. These transmissions have a first
anywhere between 6.32:1 to 7.20:1. Generally, the final drive gear is
straight through or 1.00:1 coupling the input shaft directly to the main
shaft. I've never seen a 3 or 4 speed that didn't have a 1.00:1 final drive
gear. Five speed transmissions have a 1.00:1 fourth and an overdrive. The
overdrive fifth gear is typically around 0.75:1. So, when in doubt, use
4.00:1, 3.00:1, 2.00:1, 1.00:1 for a 4 speed.

Generalizations About Automatic Transmissions

The author of this document is not particularly knowledgable about
automatic transmissions, but he is still willing to make some
generalizations. Most automatics seem to have a first gear around 3:1 and
final drive gear of 1:1. Overdrive automatics tend to have 0.75:1
overdrive.

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Author: Terry L Howe (txh3202@hertz.njit.edu)
July 18, 1996
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