727 Speedometer Gear

[Napoleon1991]

I just changed the 2.93 gears in my 65 coronet to 3.55s and I'm looking for some help on selecting the right speedo gear. The car has 28" tires on it and currently has an 18 tooth gear. It was pretty close, but always showed a few MPH too slow. I believe the gear that I need is a 21 tooth, but I want to be sure before I order one since they arent cheap.

 

[BeepBeepRR]

By the measurements you gave 3:55 gears with a 28 inch tire you need a 33 tooth gear.

Here is one on ebay for 44.00 33 tooth gear.

Should be a yellow 33 tooth gear.

The measurements of the tires are a little different here but. 27.9 and 3:55 says 33 tooth as well. Disregard the red circle it was already on the picture.

 

[Napoleon1991]

Thanks, but the 62-65 727s use different speedo gears than 66 and up. Is there a chart like that for the older transmissions?

 

[BeepBeepRR]

Well crap I learned something new today. The older ones look like a Ford/T5 speedo gear. Never knew that.

 

[toolmanmike]

Brewer has those old gears. You might need to call them for the ratio. I don't know if they are different from the later gears.

 

[BeepBeepRR]

Brewer has those old gears. You might need to call them for the ratio. I don't know if they are different from the later gears.

Here is an old gear. 62 to 65 the one pictured is a 21 tooth. And from Brewers Ebay page.

Here is the push button speedometer gear chart. This chart says you need a 20 tooth.. Which is HERE on brewers ebay store.

 

[Runcharger]

I believe you need a 21 as well.

 

[Napoleon1991]

Here is an old gear. 62 to 65 the one pictured is a 21 tooth. And from Brewers Ebay page.

View attachment 1240230

Here is the push button speedometer gear chart. This chart says you need a 20 tooth.. Which is HERE on brewers ebay store.

View attachment 1240234

Awesome! That chart is just what I was looking for. Thanks!

 

[rbkt65]

difference in the charts comes from different number of teeth on the transmission output shaft i think.