Speedometer Gear

[MRMATRIX69]

Hey guys! I have a question for you guys. I dropped the stock tranny all over the interstate a while back and got an upgraded cobra spec t-5 now. The speedo gear they said for stock gears is what we put in believing I have stock gears. It is about 10 mph slow now. I have the gear I took out of the factory tranny sitting in front of me and it is a black and has 20 teeth on it. I was wondering if anyone could tell me what ring gear ratio that goes with? The transmission has factory gear ratios and tires are the factory size. The gear he sent me I believe is for 3.55 gears which obviously aren't factory. Thanks guys for the help!

 

[02 281 GT]

That sounds like a gear for 3.08 rear gears if I recall correctly.

Try this: T5 Speedo calibration

 

[cjrpony]

It depends on which gear is inside the tranny (on the output shaft). 20 tooth (black) speedo gear and 6 tooth output gear (also black) is for 4.10 gears. 20 tooth speedo and 7 tooth output gear (yellow) is for 3.55 gears and 20 tooth speedo and 8 tooth output gear (green) is not on the chart I found but it calculates out to between 3.08 or 3.27 depending on tire size. I found these charts on this site.

Speedometer Info, FFR FAQ

I had a simular problem when I bought my car, the speedo was way off, turned out I had the wrong gear in the trans. Pull the speedocable and sender out of the trans and take a peek in there and see what color you got.

 

[MRMATRIX69]

Thanks guys! I figured I had a really tall gear set in the car. The black 20 tooth in front of me is the one that came out of the factory tranny that splattered on the interstate. I'm gonna put that one back in because the speedo was right on before. Thanks for the info on possible gear set in the rear!

 

[revhead347]

Here's what you need for all your speedo gear questions.

TCI - TECHNICAL INFORMATION: Speedometer Gears

Kurt