Speedo gear

Clutch, transmission, rear axle

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Speedo gear

Postby Bunkerhillbilly » Mon Sep 25, 2017 9:51 am

Het guys, anybody know how many teeth are on a speedo gear for 3:50 ratio rear end?? I got a bunch of em in a drawer but don't know which one I need.

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Re: Speedo gear

Postby colnago » Mon Sep 25, 2017 1:52 pm

That's going to depend on the groove count on the transmission's output shaft, the rear-end ratio (3.50, from your post), and tire size. I have a C6 with a 7-groove shaft, 4.10 gearing, and 245/75R16 tires, and I think I'm using a purple gear. This is probably not what you want to hear, but it might end up being trial-and-error for you.


On edit, Ford also used gears with long "snouts," and gears with short snouts (the narrow plastic shaft that goes beyond the geared portion). I think this helps keep the gear in the right place, relative to the top of the output shaft. As I recall, you want the short snout (could be wrong on this, so I hope someone comes in to correct if needed).
"Sugar", my 1967 Ford F250 2WD Camper Special, 352FE, Ford iron "T" Intake with 1405 Edelbrock, Duraspark II Ignition, C6 transmission, front disc brake conversion.

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