I just bought a 1989 Mustang that was originally had a manual transmission. It now has a 5.0 HO engine and 4-speed auto from a 1987 GT. The speedometer is at least 10 mph off (higher), and aside from the tach, none of the other gauges work. Any ideas what to look for?

 

sounds like you have aftermarket gears in the rear end. You need to change the VSS gear to compensate for the speedo being off

 

yeah the speedo is manually driven.... has nothing to do with anything else but a guage, gear and a cable in between

you need to pop the driven gear from the tranny and see what color it is. then you need to know what rear end gears you have by doing the driveshaft:tire revolution count

its an aod trans so it is a 8t drive gear. a 21t purple gear will work for 3.27 gears but you cant correct an aod beyond that with ford parts. it'll take the white 23t which is a jeep part and the wrong pitch so it will chew up. it'll work while it works tho. that will correct for 3.55

 

if you have 3.55 then the speedometer is yellow if you have 3.73 then its red. if the spedo is off by 10 too fast then u have 3.73 gears with a 3.55 sensor.

 

the spedometer sensor is the color not the spedometer its self sorry lol

 

he has an automatic. a red gear would only correct for 3.27's IIRC.

 

congratulations you have accomplished being 200% incorrect

first off... aod does not have red or yellow driven gears... the equivalents are:
red=purple=21t
yellow=grey=18t

this is a done issue..... until the original poster says what his REAL gears are currently. and even so i already answered it if it's more than 3.55

not to be an a$$hole but please.... dont answer from ur a$$....it helps no one and makes u look dumber

 

I just woke up, rolled out of bed and checked this thread...

read this response and was like "oh hell know... you dont talk to me like that...I know the gear switches"

Then after I cleared the crusties from my eyes, I realized that were just reminding the new guy how stereotypically retarded he is...



and I laughed.

 

c'mon bro.... u know that i know..... that u know ur ****




but glad i could amuse you......... whats this kuwait **** ? go home already, the desert sux

 

Ive only been out about 102 days so far.... still got quite a few to go.