Print Page - need to change speedo gear

Title: need to change speedo gear
Post by: Chooglin on April 21, 2010, 09:25:26 PM

I hope someone can give me advice on wich speedo gear I need

running a 8.8 with 3:27 gears and p255/60r15 tires in the rear.
speedometer seems to be around 10 mph off. when the speedometer reads 65 mph it feels more like 55 mph.I am going to verify this with my gps.
If more info is needed,let me know.

wich speedo gear should I be looking for,to get the speedometer back to being somewhat close.

does anyone have the gear I need?

Title: need to change speedo gear
Post by: hypostang on April 21, 2010, 09:30:58 PM

take a peek here
http://www.fordracingparts.com/download/charts/129.pdf

Title: need to change speedo gear
Post by: Chooglin on April 21, 2010, 10:21:46 PM

thanks,I just hope I can figure this out............lol.

Title: need to change speedo gear
Post by: vinnietbird on April 21, 2010, 11:18:43 PM

If you have a 6 tooth tranny gear (inside the tranny),you'll need a 16 tooth speedo gear.

If you have a 7 tooth gear in the tranny,you'll need a 19 tooth speedo gear

An if you have an 8 tooth tranny gear,you'll need a 21 tooth gear.

That's for 3.27 gears.

Title: need to change speedo gear
Post by: daminc on April 22, 2010, 07:21:44 AM

Here's another handy chart
http://www.latemodelrestoration.com/page/Mustang-Speedometer-Gear-Application-Guide (http://"http://www.latemodelrestoration.com/page/Mustang-Speedometer-Gear-Application-Guide")

Title: need to change speedo gear
Post by: TurboCoupe50 on April 22, 2010, 06:08:25 PM

Each tooth less on the driven gear will increase the reading approx 3-4 mph, so you should need one with three teeth less than what you have now...

Title: need to change speedo gear
Post by: Chooglin on April 22, 2010, 06:15:10 PM

thx for the help and the links guys.

Turbo
your statement has me confused (not so hard to do).

I need to decrease what the speedometer is reading.

Title: need to change speedo gear
Post by: Beau on April 23, 2010, 03:13:08 AM

this may help... (http://"http://www.ffcobra.com/FAQ/speedo.html")

Title: need to change speedo gear
Post by: TurboCoupe50 on April 23, 2010, 10:23:04 AM

OOPs I was thinking it was slow, guess I wasn't awake yet... You'll need to add teeth...

Title: need to change speedo gear
Post by: Cad-T-Bird 500 on April 23, 2010, 10:48:49 AM

TurboCoupe50 was wrong! Is this a first? ;)

First time I seen it.

TED (seems to be wrong all the time according to my kids)

Title: need to change speedo gear
Post by: TurboCoupe50 on April 23, 2010, 04:42:43 PM

Quote from: Cad-T-Bird 500;319396

TurboCoupe50 was wrong! Is this a first? ;)

I thought I was wrong once, but I was wrong... :hick:

Fox T-Bird/Cougar Forums

Technical => Misc Tech => Topic started by: Chooglin on April 21, 2010, 09:25:26 PM