T10 Speedometer Driven Gear in a '62

[Christopher R.]

Found a correct T10 for my '62. Before I go put it in (dreading that job), would like to check the speedometer gear in it. I have a 3.70 rear end. What gear, part number or color, does a 3.70 rear end take? I've got 205/75-15 tires on it - pretty close to original.

[Joe L.]

Re: T10 Speedometer Driven Gear in a '62

Chris----

Assuming that you have the correct DRIVE gear installed, you will require a GREEN, 22 tooth DRIVEN gear of GM #3860345.

How will you know if you have the correct DRIVE gear installed? Well, assuming that the speedometer gear set in the transmission now are compatible gears (not always the case if klutz's have been there before), if you take out a black, yellow, or orange gear of 23 to 25 teeth, then you have the correct DRIVE gear to be compatible with the 3860345 DRIVEN gear.

If you take out a NATURAL-colored 19 tooth gear, a BLUE 20 tooth gear, or a RED 21 tooth gear, then you must use a SILVER 22 tooth gear of GM #3987922.

Because of your requirement for a 22 tooth DRIVEN gear, you're "covered" either way since the 22 tooth gear is one of only 2 DRIVEN gear tooth counts that are available in 2 versions to accomodate BOTH common DRIVE gears.