correcting speedometer

[Natureboy]

Hey Guys,
Been ages since I posted last. Just replaced my transmission yesterday, FINALLY. No grinding, hard shifting or other problems. Which brings me to my question. How do I figure the correct speedo gear to correct my speedometer? I have stock 3.909 gears, and BF Goodrich 31x10.50-15's on it now, and in 5th gear at 65 mph on my GPS, the speedo shows 53 mph. I took out the driven gear and it has 22 teeth. I have a table for correcting the speed for 4.63 gears, and it looks like the larger the tire, the fewer teeth. Does anyone have a line on this? I can't be the only one to come across this-I'm just not that special. (Mom was right). Any help would be appreciated.

[BradMph]

Try this link
http://moldyrabbit.com/liquid/speedo_gear.html

or this one
http://www.tciauto.com/tc/speedometer-gear-calculator/

[Natureboy]

Thanks I'll check it out.

[Natureboy]

The sites you posted are helpful for figuring out gear and tire size changes but I'm looking for the mitsu speedo driven gear tooth number. I have info that they offered a few-26,24,23,22 and 21 tooth gears. By math alone I need about a 19 tooth gear and don't know if they ever had it.

[noahwins]

Sounds like you want an adapter? Can you get the tranny codes off the plate on the firewall?

These guys might be able to cut a custom adapter for you.

http://www.speedometershop.com/ratio.html

http://www.tacomaspeedometer.com/index/

[Natureboy]

I hadn't considered that route but it's sure an option. Thanks for the info!