speedo gears C-6 please help

Clutch, transmission, rear axle

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flyboy2610
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re: speedo gears C-6 please help

Post by flyboy2610 »

If you still have the speedo gear from the tranny, put it in and hook up your speedo cable. Have a friend drive in front of you on the highway at a preset speed. Then see what your speedo tells you. If yours is fast, you need a gear with more teeth. If yours is slow you need a gear with fewer teeth.
You can also go for a drive on a highway with mile markers and compare the distance your speedo says you have driven in ten miles to the actual distance.
If you speedo says you have gone 12.2 miles, but you have only gone 10, then your speedo gear needs 1.22 times more teeth your current gear.
You can find speedo gears at:
http://www.nationalpartsdepot.com/
Look in the online catalog on page 150.
Hope this helps. :)
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re: speedo gears C-6 please help

Post by Comet »

The right gear is a function of your R&P gears, the tire dia. as well as the tranny.
Check this out for some of the calculations (I know it's a chevelle link, but the info. applies :P ). There are several other web pages with similar info, so if this doesn't help, do a search for "speedo gear chart."
http://www.chevelles.com/shop/speedo.html

Or, just call Tacoma Speedometer with the axle and tire info and they'll set you up-(253) 582-3890
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re: speedo gears C-6 please help

Post by magnethead »

Speedo Error Percent = (difference between actual and indicated speeds / asctual speed) * 100
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re: speedo gears C-6 please help

Post by edgar.ford.67 »

I have a 67 ford truck with a c-6 tranmission...i changed my differiental to a 2.50, i did have a 3.50.. i need help setting my speedo gear
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re: speedo gears C-6 please help

Post by FORDification »

There's a lot of online info about how to figure out what speedometer gears you need when changing axle ratios. Here's a couple:

http://www.boss302.com/speedo.htm

http://www.tciauto.com/tech_info/speedo_gears.htm
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