Installing 4.10s... Correcting speedo.

[97cobra1]

Like title says, i'm putting 4.10s in the car while it's in getting the rear end redone.

How do i correct the inaccuracy of the speedo? I'm going from 3.73s from a previous owner, and i'm unsure of how he went about correcting the difference when he installed.

What are my options?

 

[fast02gt]

use a speedo gear i believe its the white 21 you need. look on 50rest.com they have it. people will tell you "oh it will get chewed up" or "it doesnt work" I have it and it works fine plus its cheaper than a speedcal and less of a hassle.

 

[oem]

SCT programmer.

 

[fast02gt]

SCT programmer.

That's only a 99-up car. He has a mechanical speedo.

 

[97cobra1]

Thanks, are you sure it's the white 21 tooth? Is it still going to be a little bit inaccurate? By how much?

 

[rich5150]

Thanks, are you sure it's the white 21 tooth? Is it still going to be a little bit inaccurate? By how much?

It's actually 23. Check the link

Steeda 392-STE-17271-D - Steeda Speedometer Drive Gears - Overview - SummitRacing.com

 

[phinhead34]

I had the white one, it was a little bit off on 17" wheels but nothing major. If you want it to read 100% accurate you need the speedcal. It takes 10 min to change the speedo gear.

 

[CJK440]

The speedo gear depends on what tranny is out of. The output shaft has a different tooth count between cobra and gt. 4.10's and a cobra t45 will require a white gear.

I just took out a white gear when I swapped to 3.73's and the teeth were pretty worn after 5k miles. No chips but they were thin.

Sent from my Vortex using Tapatalk 2

 

[97cobra1]

i ordered the 23 tooth for the time being. if i wasn't replacing the LCAs with MM parts i'd get the speed cal now. couple of other things above a speedcal priority wise right now.

Thanks for the help though ya'll. Much appreciated.

 

[VMC]

I use the "speedometer" app on my iPhone when I drive the Cobra lol ...be ready to install the speedcal soon. From my experience, the 23 tooth gear wore out pretty quick when I was daily driving it.

 

[fast02gt]

Good save on the 23 white gear.

 

[Dogshark]

I use the "speedometer" app on my iPhone when I drive the Cobra lol ...be ready to install the speedcal soon. From my experience, the 23 tooth gear wore out pretty quick when I was daily driving it.

Good idea. Not sure how accurate that is, but I like the idea.
Who cares exactly how fast your goin anyway. oke:

 

[WhiteFoxGT]

so for a cobra, is it the 21 or 23. this thread is confusing

 

[WhiteFoxGT]

????

Im about to place my order, some clarification would be great

 

[4vRedone]

Its the 23 tooth I didn't knoe it was different from the gt one '

 

[Mustang Matt]

Hang on to your factory gear if it's not torn up. If you get a speedcal later you can swap it back in and it will be more reliable than the higher tooth gears.