Speedo Calibration Gear??

needafox

New Member
Mar 23, 2006
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Sorry guys, this may seem like a newbie question. Thats because it is. I am new to the 5.0 world. I just sold 2004 Subaru STi and found a clean fox to start playing with. The car is an 89' GT, T5, has a set of richmond 3.73's and 17"x9.5" cobra r's with 245/45/17 tires. What speedo gear do I need to recalibrate the speedometer so it doesn't keep racking up miles like crazy? Thanks
 
Use a white 23 tooth gear, available from Jeep dealers. Not the best, but it isn't expensive & will work. Some guys find that they chew up quickly and have a short service life.
EDIT: the 21 tooth is a better match for 3.73 gears after checking http://www.hanlonmotorsports.com/t5speedo.asp calibrator.

The stock range of speedo gears work correctly with a limited range of tire sizes.

See http://www.corral.net/tech/gearcalc.html for more help

Check to see if there is a speedometer shop in your area. If there is, ask about the Stewart-Warner speedometer gearbox. I believe it is either a 777 Series Drive Joint Kits and Parts or 666 Series Drive Joint Kits and Parts. It is a small gear box that fits between the speedo pickup gear on the transmission and the speedometer. It has quick change gears that allow you to choose almost any tire size and rear end gear ratio you want. This will allow you to get the accuracy with within 1%-3%. The drawback is that it isn't cheap.
Please excuse the typo (their's, not mine) in the following picture - it should read Custom ratio adapters, not Custom radio adapters.
ratios.jpg

See http://www.gaugeguys.com/ratioadapt.htm for more info.
 
I have heard from other people that the red 21 tooth gear is going to be the one I want to use. What is the difference and why would one be better fro my setup than the other would?