Speedo Worm Gear

[wideglide38]

Does anyone have an catalog info for a speedo worm gear stamped with the following number SW 447516? I'm assuming Stewart-Warner for the "SW". I've searched the web and no luck. The gear looks like its an 8tpi (for '62-'69 4-speeds). Hoping someone can help me ID the gear.

Thanks, William

[wideglide38]

I checked the worm gear with a pitch gauge and it measures 9 tpi. Odd thread count as Palmer's book doesn't reference a 9 tpi gear unless I missed somewhere else in his book. Palmer's 4 tpi (E'62-'69 w/ 13T drive), 7 tpi ('36-'61 w/ 7T drive & '69-'80 w/ 23T drive), 8 tpi copper plated (L'61 w/ 23T drive) and 20 tpi ('37-'52 45" solos).

[Rubone]

Palmer's references are not TPI, they are total number of teeth machined on the gear. Count the ends of the spirals.

[wideglide38]

Thanks, you're right. Spiral end count is 4.