What sppedo gear for 3:73's?

9 Deuce GT

Member
Dec 10, 2003
550
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16
Geneva, NY
I bought some 3:73 gears for my '92. Just wondering which speedo gear I need. Ford Racing's catalog does not list a gear for my setup, but I saw some that said they were for 3:73's for '90 and newer T-5's at Carlilse this weekend. What are you guy's using?
 
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Yeah, you'll never be "right on" with 3.73s and a 1990+ T-5 with a 8 tooth drive gear. A 23 tooth is accurate with 3.55's, but not 3.73s... Only thing you can do is pull the tail housing off and put a 7 tooth drive gear on, or take it to a speedo shop and have them make you up an adapter box.
 
slo65 said:
what about a 88 t-5, its a 7tooth trans and a 21 tooth gear right? just had my speedo put in with the new 21 tooth gear he said its 6% off


good thing i foudn this thread i was just gonna make one but i did a search (good ol search button) i have a 88 mustang, it has 3.73's and 245/50R16's

what gear do i need peoples? i heard somehting about a dodge gear that works or something
 
88_GT_5_oh said:
good thing i foudn this thread i was just gonna make one but i did a search (good ol search button) i have a 88 mustang, it has 3.73's and 245/50R16's

what gear do i need peoples? i heard somehting about a dodge gear that works or something

he mentioned something about if they made a 22 tooth gear it'd work, but they dont make one :shrug: i remember going next to my friend in his is300 and him calling out "40" and that was 2k in 4th gear for me, i did the same in my car and it's on, so its close enough for me, i dont really take my car that fast, i just do 1-3 gear bursts here and there
 
88_GT_5_oh said:
so jsut go to ford and get the 21 tooth one?

my buddy works at ford and they had no clue what gear i needed, damn ford techs lol

that's what i did, it's red... yea i went to a ford dealership, bought the gear, and lost it, so went back a couple of months later and they had no clue what i was talking about :shrug: i see your in canada eh, it would make a difference in kilomaters kilammmaters.... killometers.... keelo.... i give up :nonono:
 
lol.. nah it won't really mater it still has the MPH in small numbers, as oposed to yours with KMH in small numbers, its just reversed,

but my speedo goes to 110 MPH (figure out why ford did that lol)
 
No, some of you are getting confused. With a 7 tooth T-5 (85-89) get the 21 tooth red gear and the speedo will be perfectly accurate. If you have a 90+ T-5, you have an 8 tooth tranny gear and you have to use the 23 tooth speedo gear....but it won't be perfectly accurate. Also if you have a Superduty T-5 or T-5Z then it also has a 7 tooth tranny gear.
 
maverick0716 said:
No, some of you are getting confused. With a 7 tooth T-5 (85-89) get the 21 tooth red gear and the speedo will be perfectly accurate.


thats my setup and he said its not completely accurate, 6% to quote him, i'll have to check it out with some friends driving a long side maybe, its close enough for me :banana: