Vintage Mustang Forums banner

1 - 5 of 5 Posts

·
Registered
Joined
·
3,980 Posts
Discussion Starter #1
Hi Guys,

Last time under the car we saw that the spedo cable was not hooked to the AOD--car originally had a C4. 2 questions, what spedo gear will I need for a 3.80 gear (I assume that a gear for 3.7's will be close enough and I believe that it will be a red color), and, will the cable plug into the AOD. I have a feeling that it won't. Anyone out there with advice to making a spedo work with an AOD??

Thanks!!
 

·
Registered
Joined
·
1,712 Posts
A few answers for you...

The cable and speedo gear for an AOD is the same as used for a C4 and FMX (probably others too, I just happen to know those for certain)...

As to what gear you need, you did not supply enough information because the rear tire diameter/height matters too...

Your Speedometer wants to turn 1000 RPM at 60 MPH. The AOD output shaft will likely have 7 teeth (there was an 8 tooth output shaft, it is not common). You can plug in your tire height and rear end ratio into any of the online calculators to determine the number of teeth needed for the driven gear...

Here is one such calculator:

Speedometer Gear Calculator

Good luck,
-Rory
 

·
Registered
Joined
·
8,138 Posts
Steeda has a page on their website that has a chart too.
 

·
Registered
Joined
·
3,980 Posts
Discussion Starter #4
Thanks Guys!! After plugging in the numbers it looks like I need a 20.6 tooth gear for the 3.80's so I will go with a 21 tooth drive.

Thanks!!
 
1 - 5 of 5 Posts
Top