Gear, Transmission Speedometer

[Michael S.]

What would be the rear end ratio for a orange gear with 25 teeth.
Thanks, Michael

[Joe L.]

Re: Gear, Transmission Speedometer

What would be the rear end ratio for a orange gear with 25 teeth.
Thanks, Michael

Michael-----


It varies a bit depending upon year model and specific application but, in general, the 25 tooth orange DRIVEN gear is used with 3.70:1 or 4.11:1 rear gear ratios.

[Edward J.]

Re: Gear, Transmission Speedometer

Mike, you may have to post alittle more info, 4spd,auto, is this the drive gear inside trans or driven gear in the housing thats orange?year or car also

[Michael S.]

Re: Gear, Transmission Speedometer

Mike, you may have to post alittle more info, 4spd,auto, is this the drive gear inside trans or driven gear in the housing thats orange?year or car also

It's a NOS part that I never used. It goes inside the side of the 4-speed. I looked it up in the GM Parts book which told me it's for a 1967 corvette w4:10 ratio. The Part # is 3860347
Thanks, Michael

[Wayne M.]

Re: Gear, Transmission Speedometer

It's a NOS part that I never used. It goes inside the side of the 4-speed. I looked it up in the GM Parts book which told me it's for a 1967 corvette w4:10 ratio. The Part # is 3860347
Thanks, Michael

Michael -- are you sure of color ? In my parts book, 3860347 is a yellow, 24-tooth driven gear, usually found in C2's with 4.11 final drive.

[Michael S.]

Re: Gear, Transmission Speedometer

Michael -- are you sure of color ? In my parts book, 3860347 is a yellow, 24-tooth driven gear, usually found in C2's with 4.11 final drive.

Wayne, I can send you a picture.

[Joe L.]

Re: Gear, Transmission Speedometer

It's a NOS part that I never used. It goes inside the side of the 4-speed. I looked it up in the GM Parts book which told me it's for a 1967 corvette w4:10 ratio. The Part # is 3860347
Thanks, Michael

Michael-----

It's applicable to 4 speed as well as 3 speed manual transmissions. It's not unique to 1967 Corvettes by any means. It's applicable to virtually all Chevrolets of the period.

[Joe L.]

Re: Gear, Transmission Speedometer

It's a NOS part that I never used. It goes inside the side of the 4-speed. I looked it up in the GM Parts book which told me it's for a 1967 corvette w4:10 ratio. The Part # is 3860347
Thanks, Michael

Michael------


If the gear is orange and 25 teeth but the package says GM #3860347 on it, then either it was mis-packaged (if the package seal is unbroken) or someone switched it (if the package seal is broken). The GM #3860347 is a yellow, 24 tooth gear. The orange 25 tooth gear is GM #3860348.

[Wayne M.]

Re: Gear, Transmission Speedometer

Here's a shot of the orange 25-tooth. Does look a little "yellow-y".

[Michael S.]

Re: Gear, Transmission Speedometer

Here's what I have

[George C.]

Re: Gear, Transmission Speedometer

Wayne,
Can I have the parts in your photo? I bet I could get my speedometer to work correctly with that assortment.

I believe my car was originally equipped with a 4.11 gear; it is now sporting a 3:36. So I read about 17% low on the speedometer.
I am planning to remove the transmission this summer, change out the drive gear, and get the correct driven gear installed.
George

[Joe L.]

Re: Gear, Transmission Speedometer

Here's what I have

Michael------


If that gear has 25 teeth on it and I fully expect it does, if it originally was supplied in that box then it was mis-packed. However, I doubt that happened. Much more likely someone took it out of another box and put it in that box. The part number of the gear pictured is 3860348.