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- - Speedo Cable Driven Gear (https://67-72chevytrucks.com/vboard/showthread.php?t=408219)

Sinister Chevy

06-19-2010 11:23 AM

Speedo Cable Driven Gear

Wow! This one hurts my head. My 69 c-10 speedo is reading way too fast. I know the gear ratio (3.07) and the tire diameter (29") but how do I know which speedo cable driven gear to get without taking apart the transmission to look at the drive gear.

swierker

06-19-2010 12:43 PM

Re: Speedo Cable Driven Gear

I have the same problem and I searched a little. This link may help but you need to know the drive gear as well.

http://www.tciauto.com/Products/Tech...eedo_gears.asp

This may help if you want to estimate it without knowing the drive gear. I haven't done it yet though.

http://www.tciauto.com/Products/Tech...eedo_gears.asp

If you try the estimating method let me know how it turns out.

Dan

Sinister Chevy

06-19-2010 01:09 PM

Re: Speedo Cable Driven Gear

Thanks, I will give it a try. If I get the existing driven gear teeth qty, which is easy, I can calc the driven gear teeth. THX again.

geezer#99

06-19-2010 03:08 PM

Re: Speedo Cable Driven Gear

1 Attachment(s)

Here's what I did. Had the wife drive ahead of me at 100kmh. My speedo said I was going about 125kmh(converted). I was about 25% to fast. Bought a ratio adaptor off ebay for 60 bucks that was 27% adjustment. Works good and didn't have to tear into the tailhousing. Pic included. It's the little squarish thing in the pic.

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