3.73 gears installed today but speedometer

[Bob H]

I had the local Ford dealer install Ford Racing (3.73) gears in my 2003 GT today but according to them they were unable to change the computer to reflect the new gears so the speedometer/odometer would read correctly. I know many of you have changed the gears and I thought it was a simple computer adjustment to get the speedometer to read correctly on the 99's and newer. Please let me know what I need to do and who I can take it to.

 

[Beau]

they should have been able to reflash your ECU to make the change.

but what you can do is buy a speedcal from brothersperformance.com or dallasmustang.com OR send your ECU to someone like T & J Performance and get them to reflash your ECU for you.

 

[krly79]

they should have been able to reflash your ECU to make the change.

but what you can do is buy a speedcal from brothersperformance.com or dallasmustang.com OR send your ECU to someone like T & J Performance and get them to reflash your ECU for you.

They should have been able too. Of course, we are speaking of a dealer right?

 

[03redfiregt]

the dealer did my gears too and they also coud;nt fix the speedo. though they tried several times. Your going to have to either get speedcall, or get a chip or programer like i did.

 

[Beau]

They should have been able too. Of course, we are speaking of a dealer right?

dealers = teh suck

 

[GOLDENPONY]

Gears

So how do you like the gears? My car is getting 3.73's installed as we speak.

 

[Bob H]

So how do you like the gears? My car is getting 3.73's installed as we speak.

The car pulls alot stronger in 3rd & 4th gears but I really haven't put the pedal to the metal since I only have 300 miles on the car. Just putting all of the peices in place for the KB 9psi supercharger in a couple of months.

 

[BlackVert]

The car pulls alot stronger in 3rd & 4th gears but I really haven't put the pedal to the metal since I only have 300 miles on the car. Just putting all of the peices in place for the KB 9psi supercharger in a couple of months.

I wish i had gone with 3.73s. 1st and 2nd are just too short for my liking. Good luck and have fun!

 

[BlackVert]

I had the local Ford dealer install Ford Racing (3.73) gears in my 2003 GT today but according to them they were unable to change the computer to reflect the new gears so the speedometer/odometer would read correctly. I know many of you have changed the gears and I thought it was a simple computer adjustment to get the speedometer to read correctly on the 99's and newer. Please let me know what I need to do and who I can take it to.

Why is it that the 96-98 also has the EEC V computer, but you can't fix the speedo the same way you can with the 99+?

 

[Dan_Soprano]

Why is it that the 96-98 also has the EEC V computer, but you can't fix the speedo the same way you can with the 99+?

the 99+ GTs have an electronic speed sensor. the older ones had a gear/cable driven speedo.

 

[Dan_Soprano]

The car pulls alot stronger in 3rd & 4th gears but I really haven't put the pedal to the metal since I only have 300 miles on the car. Just putting all of the peices in place for the KB 9psi supercharger in a couple of months.

Bro, you are going to wish that you kept the stock 3.27's with the KB. I almost went with 3.73's also, but I am glad I didn't now. Traction will be a serious issue for you. PM el_kid_1 , he has the KB 9psi and the 3.73's. IMO the stock 3.27s are perfect for the KB.

 

[madmatt]

If you dont mind me asking, how much would a dealer charge to put in a set of gears? Thanks

 

[68 & 00 GT]

$300 - $500

Had mine installed for $200. Total was $400 w/ parts, and everything, and I love them. Hope they're OK for my upcomming s/c. I've planned my car that way so I should be OK, but I'm going with a Novi 2 K, not a KB. I have my perfect stock 327's. Anyone ?

 

[00gtconv]

Ford

Ford is not able to make odemeter adjustments related to the gear ratio. They do have the ability to make some minor changes to the odemeter conserning slight tire size changes( but wont).

Spedo shops do not make adj. to elect. controlled speedometers.

You will need a chip when you get your blower. Find the place you are getting your blower installed or tuned. Ask them what type of chip to get or see if they supply them. Program it for your current gears and setup. Then have it reprogramed when you get your blower.

Most places will charge little or nothing to reprogram your chip, if you are doing business with them.

Or :
http://www.dallasmustang.com/index....gory_Code=L_Drivetrain_SpeedometerAccessories

 

[BlueStangGT]

the 99+ GTs have an electronic speed sensor. the older ones had a gear/cable driven speedo.

Actually, from 96 and newer they all have electronic sensors. The difference is where the electronic signal goes from the sensor in the tranny. For 99-up cars the signal goes directly to the computer and the computer controls the speedo / odo etc. functions. For 96-98 the signal goes from the sensor directly to the speedo / odo cluster and thus is not controlled by the computer.

 

[speed545]

Ford cannot correct speedo after a gear change in a mustang because theirs computer/programmer we re not design to do so. But they will able to do it if you have a F250 equipped to tow a fifth wheel and you had them change the stock gear in the truck.
Ford didnt built theirs computer to do in a mustang but able to do it in a truck

 

[NewEngPatsFan]

Same here - I had 3.73s installed and a dealer couldn't reflash the ECU. I went with a Dallas Mustang SpeedCal. Glad I did - when checking it against measured mile markers, I found the speedometer was off by over 2% from the factory. I was able to bring it in under 0.5% with the SpeedCal.

Love the gears BTW. Car actually feels smoother, much better throttle response, as there is no lugging between shifts at low to moderate throttle anymore.