Speedo Gear Replacement

larrendeuce

Member

Sep 13, 2003

649

1

19

Southern NJ

Sep 13, 2004

#1

• Sep 13, 2004

• #1

I am going to switch to 3.73 gears. I have an AOD transmission with the 8 tooth drive gear, so I can only be accurate up to a 3.55 with the 23 tooth white driven gear. Is the drive gear changable to the 7 tooth?

 

_jb_

New Member

Mar 4, 2004

808

0

0

Michigan, Berrien County

Sep 13, 2004

#2

• Sep 13, 2004

• #2

Try this site,

http://www.geocities.com/mgnedell/notchback/tech/speedo.html

 

TRWXXA

Member

Jan 18, 2003

190

1

19

RIGHT BEHIND YOU!!!... Made you look.

Sep 13, 2004

#3

• Sep 13, 2004

• #3

Unless your tires are smaller than stock, the 23-tooth gear is what you need for 3.73s (a 21-tooth gear is for 3.55s).

Your speedo will still be about 5 - 8% off, depending on tire size, but the 23-tooth gear gets you close.

The AODs have the drive gear machined onto the output shaft, so you'd have to change the entire shaft rather than slipping a new gear onto it.

 

larrendeuce

Member

Sep 13, 2003

649

1

19

Southern NJ

Sep 13, 2004

#4

• Sep 13, 2004

• #4

Thanks. My friend has a couple 87-88 Thunderbird AOD's that I can get the output shafts from. Are they compatable?

 

TRWXXA

Member

Jan 18, 2003

190

1

19

RIGHT BEHIND YOU!!!... Made you look.

Sep 13, 2004

#5

• Sep 13, 2004

• #5

larrendeuce said:

Thanks. My friend has a couple 87-88 Thunderbird AOD's that I can get the output shafts from. Are they compatable?

Click to expand...

You might want to research that online. Please don't take my word for it, but I thought that all the AODs were essentially the same, though some got different gearing for truck applications.

Anyone else more familiar with the AOD tranny family?