Speedometer Driven Gear

[Don C.]

Looking for help with what Manual Speedometer Driven Gear I should buy ?
I'm looking on Zip Corvettes and the gears start at 18 teeth through 24 teeth.
1960 corvette W/373 gears in rear diff. borg warner T-10 4 speed stock tires.

[Joe L.]

Re: Speedometer Driven Gear

Looking for help with what Manual Speedometer Driven Gear I should buy ?
I'm looking on Zip Corvettes and the gears start at 18 teeth through 24 teeth.
1960 corvette W/373 gears in rear diff. borg warner T-10 4 speed stock tires.

Don-----


The gear you require is a 22 tooth GREEN gear. However, this assumes that the transmission was originally equipped with a DRIVE gear for 22-24 tooth DRIVEN gears (i.e. for a 3.70 or numerically higher rear ratio).

However, you're in luck even if it was not. That's because if it was originally built for use with 3.55:1 or numerically lower gears, you can then use a 22 tooth SILVER gear. The 22 tooth gear is the only tooth count gear that's available for both series of driven gears (i.e. 18-21 and 22-24).

[Don C.]

Re: Speedometer Driven Gear

Don-----


The gear you require is a 22 tooth GREEN gear. However, this assumes that the transmission was originally equipped with a DRIVE gear for 22-24 tooth DRIVEN gears (i.e. for a 3.70 or numerically higher rear ratio).

However, you're in luck even if it was not. That's because if it was originally built for use with 3.55:1 or numerically lower gears, you can then use a 22 tooth SILVER gear. The 22 tooth gear is the only tooth count gear that's available for both series of driven gears (i.e. 18-21 and 22-24).

Thanks Joe
very helpful

[Wayne M.]

Re: Speedometer Driven Gear

Don, Joe -- I've never touched a T-10 in my life, but looking at the parts catalogs, there seems to be a distinct break in the design of the driven gear 'fitting' after 1960 (refer to the steel 'bullet' pictured in the thumbnail with a 22-tooth green plastic driven gear). Up to and including 1960, the fittings are 2_5/8" O.L., according to the Chev catalog.

Post -1960 and throughout the Muncie era (at least) the 1.79" O.L. unit shown was used. Likewise, although the speedometer DRIVEN gears were the same tooth count and color in the pre-61 era, I believe they were of a different design (and certainly a different part #) to accomodate the longer "bullet" for 1960 and earlier.

Again, I could be completely wrong, as this is based on my reading of catalog info.