3.73 speedometer gear change?
 

wats up guys , i just got my 3.73 gears installed today and i wasnt as impressed as i thought i would be. first thing im driving my car home and my speedometer was reading 70 mph and i only felt like i was going 55. i called my girlfriend who was following me and asked her wat hers said and she said 55. so i jumped on the phone with the guy who installed the gears and he said that i need to go to ford and get a new gear for the speedometer. i never heard of this before and i was wondering if he is BS'in me. wat didnt impress me about the gear change was that i thought there would a grand cloud of smoke and chirping into second with the swap. i didnt no this but the car came with 3.08's alot of people told me that the stock was 2. sumthin. i also added the aluminum drive shaft. it really works in cutting down on the interior noise that i used to get. is there sumthing that i left out that i should have added with the gear swap? ne answers would be greatly apreciated.

thanks, danny

oh yeah i forgot to ask one more thing, does the gear change affect the rpm read out like it does the speedometer or does it stay the same.

Well you do need a new speedometer gear for the tranny. I believe it's a 21 tooth gear for 3.73's. This is because your wheels and your transmission are now turning faster after the gear swap and are therefore making your speedometer read faster. With the correct speedometer gear, it will go back to reading correctly.

Your RPM's will read higher than they were before, but this is only because they REALLY ARE higher. So your tach is still accurate, (well as accurate as a stock tach is anyway)

Get the speedometer gear (between $10-$15) and your all set

Yes you do have to change the speedo gear. Unless you are comfortable driving around with the error on your dashboard.

As far as your un-impression... I think it's because like you said, you were starting off with a higher gear from the get-go (3.08). Most people's stangs are 2.73's, and a change from teh 2.73 to 3.73 is a bit more of a difference noticed (i.e. seat of the pants) than the change from 3.08 to 3.73. Maybe you shoudl have gone for the 4.10's.

You need a 7 tooth output shaft gear and a 21 tooth cable gear. That is what i did and my speedo is right on the money.:D

OK, guys. I need help here to. What about a 160 spedo. That came on my X-trooper mustang. I have 3.08's now. If I get the 3.73's or 3.55's what gear should go on my tranny.



thanks.

As said earlier you will need the 21 tooth for the 3.73's. With the 3.55's I think you need a 23 tooth which you can only get out of magazines because Ford doesn't sell it. However, my friend had this one and it wore out all the time because the teeth are so small to get all 23 on there. He eventually went with the 21 tooth and his speed is close to accurate.

I also have the speedo problem, I have 3.73's in my car and the speedo is marking higher than it really is going which from what I hear is normal untill you put in the right speedo gear....

my question is if the odometer should be affected by the 3.73 rear gears ?cause its racking up the miles fast as well.

From what I understand I need the 23 tooth (white) speedo gear for my 95 gt vert (manual) right? Will this fix both the speedo and odometer or do I need something else to fix the odometer?

One last question how hard is the speedo gear instal, I really have very little experience dealing with car stuff, but I want to learn, so if its not too hard could someone point me to where I could read on how to do the instal (or just let me know how to do it) Thanks for any replies and sorry for so many questions.

The white 21 tooth speedo gear can be found at your local Jeep dealership. I know it sounds crazy, but this is the exact same part that you find listed in the magazines and online.
http://forums.mustangworks.com/images/icons/icon2.gifPart # J3167393
It cost me $15, was in stock, and in my car (AODE w/ 4.10s) the speedo is dead on. :cool:

FYI: For T5's:
 

4.10's require the Black 22 tooth gear (and a black 6 tooth driven gear).
3.73's require the Red 21 tooth gear.
3.55's require the Black 20 tooth gear, EXCEPT for the 1993 Cobra, which requires a 23 tooth gear (Saleen Performance Parts sells them).
3.27's require the Pink 19 tooth gear.

Take care,
-Chris

correct speedometer gear
 

According to Promotion Powertrain gear usage chart,if you have T-5 transmission from 82-1995 with yellow 7T input shaft gear and you have 3.08 rear end axle gear ratio you will need driven cable gear with 18T
3.27 vs 19T
3.55 vs 20T
3.73 vs 21T
4.10 vs 23T

Driven cable gear color code:
16T = wine
17T = white
18T = yellow
19T = pink
20T = black
21T = red
23T = white
I just installed 4.10 gear on mine upgrade from 3.08 and boy! what an improvement on acceleration but RPM is much higher than before also but hey!,that is the price to pay for neck snapping feeling,right?

when I change the speedo gear will that fix my odometer too so it wont count miles fast or am I just gonna have to live with that?

i believe miles are counted by the rotation of the tire and have nothing to do with gears or anything of the sort...could be wrong but i think thats the way it goes

The odometer is run by gears from the speedo reading. When the speedo gear is changed the milage will start reading correct again. I'm trying to remember, which plug was it for the speedo gear?? He'll need to know that too....