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Hogan
07-17-2017, 03:39 PM
I have completed a third member swap in my 1960 Thunderbird going from a 3.10 (stock) to a 2.75. I am now searching for a speedo driven gear for my cruisomatic transmission so the speedometer reads more accurately. Using the following gear calculator, it appears that I need a 17 tooth gear with my 26.7 diameter tires and 8 tooth gear in the transmission.

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

Does anyone know the gear type (Type 2, 2A, 3, or 3A) that the cruisomatic transmission uses? Next, would anyone know the part number that would have 17 teeth? Any information or assistance would be much appreciated.

Respectfully,

Lance

jopizz
07-17-2017, 05:02 PM
The Ford parts book doesn't list a type, however for a COM transmission the part number for the 17 tooth gear is B8A-17322-B. The color is brown. Hope this helps.

John

jopizz
07-17-2017, 05:48 PM
If you can't find that part number I found some more info in a later parts manual. It lists a 17 tooth COM gear as C3DZ-17271-B; green or white, type 3A.

John

Hogan
07-17-2017, 09:52 PM
John,

Thanks for the part number. I will call my local Ford dealership tomorrow to see if the part is available.

Lance

jopizz
07-17-2017, 10:12 PM
I doubt your local dealer will have it. If they don't try here.

http://www.macsautoparts.com/ford_thunderbird/ford-thunderbird-speedometer-driven-gear-17-teeth-white-type-3a-1964-66.html

You can probably find them on Ebay a little cheaper.

http://www.ebay.com/itm/NOS-FORD-SPEEDOMETER-GEAR-WHITE-17-TOOTH-C3DZ-17271-B-/282494826051?epid=1622243000&hash=item41c600f643:g:WTIAAOSwn-tZKCvJ&vxp=mtr

John

Hogan
07-18-2017, 10:44 AM
I ordered the gear on ebay this morning. Thanks for the link!

Hogan
07-27-2017, 12:36 PM
I was able to order both gears. When I received them, I noticed that they were of different diameters. Specifically, the B8A-17322-B measured .841 in diameter (outside of teeth) and the C3DZ-17271-B measured at .770 in diameter.

I measured the gear that I am replacing and it measured .860. So, I installed the B8A-17322-B gear as it was closer to the original size.