Fox T-Bird/Cougar Forums

Technical => Drivetrain Tech => Topic started by: vinnietbird on August 02, 2008, 07:07:27 PM

Title: Which speedo gear ???
Post by: vinnietbird on August 02, 2008, 07:07:27 PM
O.K.,I did the T-5 swap,I have 3.55 gears.Which speedo drive gear do I need?Thanks guys.
Title: Which speedo gear ???
Post by: gumby on August 02, 2008, 09:22:49 PM
http://www.ffcobra.com/FAQ/speedo.html
Title: Which speedo gear ???
Post by: jcassity on August 02, 2008, 11:29:51 PM
Per my DIY link................... old topics of interest i saved.


MISC SPEEDO GEAR INFO
---thunderjet302
For those of you who have installed 3.73 gears with your stock AOD you know how hard
it is to find a speedo driven gear to make your speedo close to accurate. In reality a
24 tooth gear would put it dead on but a 23 tooth gear makes it with in 1-3 mph of being
correct. The only problem was that there was no 23 tooth auto trans driven gear avaliable
from Ford. You either had to use a 21 tooth gear like I did and accept the 6-7 mph
difference between what the speedo said and your actual speed or use a 23 tooth gear
for a T-5 which would wear out fast. There is a solution though. I found a 23 tooth
AOD driven gear at Mustangs unlimited. I ordered it and it looks just like my 21 tooth
gear with 2 more teeth. I installed it and vola my speedo is almost right on. Here's
the link if anyone is interested. ---thunderjet302

--turbocoupe50
Cool... But I have the later super coupe AOD with a 7 tooth output.
A 21 works fine for me.--turbocoupe50
Title: Which speedo gear ???
Post by: vinnietbird on August 02, 2008, 11:30:19 PM
Thanks a lot.I'll be looking at the gear I removed from the tranny and see if it'll work,or,just buy a new one.
Title: Which speedo gear ???
Post by: vinnietbird on August 02, 2008, 11:32:07 PM
jcassity,I have 3.55 gears,not 3.73's.I need the little gear for those .
Title: Which speedo gear ???
Post by: jcassity on August 03, 2008, 12:33:25 AM
dont kill the messenger,,
Title: Which speedo gear ???
Post by: vinnietbird on August 03, 2008, 12:44:02 AM
No killing.I was just clarifying.I appreciate any and all help from you guys.No worries,all is good.
Title: Which speedo gear ???
Post by: 5.0 tbird on August 03, 2008, 10:23:25 PM
Check this out. This is what I use to find my speedo gears.

http://www.fordracingparts.com/download/charts/129.pdf

I think the last gear I bought from Ford was 9.00. :D
Title: Which speedo gear ???
Post by: gumby on August 03, 2008, 11:13:54 PM
$9????? wow, you got hosed.

16T gear for mine cost me $3.25 from ford. :flip:
Title: Which speedo gear ???
Post by: jcassity on August 03, 2008, 11:34:56 PM
so,,
at 16tooth speedo gear for 355 rear gears?
Title: Which speedo gear ???
Post by: gumby on August 04, 2008, 08:51:55 PM
Quote from: jcassity;230477
so,,
at 16tooth speedo gear for 355 rear gears?
if you are referring to my post, no. im running 3.27's

also, if you follow the link i posted you will find a calculator that shows there is more involved to pickin a speedo driven gear than just knowing the rear gear set ratio.
in other words, there is not enough information supplied in the original post to determine what driven gear the OP needs.
Title: Which speedo gear ???
Post by: vinnietbird on August 04, 2008, 09:00:50 PM
I got the info I needed from the chart shown.I should have the speedo gear in a couple of days,and I'll post the results and which gear I end up using.