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Speedometer gear help!!

  • Thread starter Thread starter Twistedimage
  • Start date Start date Apr 16, 2009
T

Twistedimage

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Apr 12, 2009
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St. Louis
Apr 16, 2009
#1
  • Apr 16, 2009
  • #1
Ok so i got 373 gears and i went to change my speedo gear. Well i ordered TCI 881004 - TCI Ford Speedometer Gears , it didnt fit for me , I dont think im putting it on wrong... it just seems to short. Did i get the wrong gear? please help! Thanks, btw its an AOD if that makes a dif.
 

93tealstang

Founding Member
Jan 24, 2002
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McSherrystown/Hanover Pennsylvania
Apr 17, 2009
#2
  • Apr 17, 2009
  • #2
This is a common problem when 3.73's are installed in a 90+ car which I'm assuming is what you have. The gear you've linked is the gear most people THINK will work with 3.73's but it actually doesn't. It is actually a factory gear for a Jeep but in the past few years it has been marketed for fitment of a Ford. If you can even get it to fit, it will only work temporarily since the teeth on it will not mesh correctly. You'll actually need to change out the transmission drive gear and then install an 18 tooth yellow speedo gear.
 
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Twistedimage

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Apr 12, 2009
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St. Louis
Apr 17, 2009
#3
  • Apr 17, 2009
  • #3
Well i got an 89, so there no gear what so ever that will fit without getting a new tranny drive gear? The gear just seemed to short and the clip wouldnt go on.. im not sure if i put it on right but should it fit on ? If so ill put it on but it seemed like its was maybe 1 cm to short to go down.
 

93tealstang

Founding Member
Jan 24, 2002
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Apr 17, 2009
#4
  • Apr 17, 2009
  • #4
Ok then, in your case with the 89, a red 21 tooth should do the job and also fit correctly.
 
T

Twistedimage

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Apr 12, 2009
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St. Louis
Apr 17, 2009
#5
  • Apr 17, 2009
  • #5
Ok, but should that white 23 tooth gear fit? Because if it supposed to work i would like to use that one. So the question is will the 23 tooth gear i got work/fit?
 

Beasty306GT

Active Member
Dec 19, 2002
671
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Oxford,Mass
Apr 17, 2009
#6
  • Apr 17, 2009
  • #6
This is the one you need GEAR, SPEEDOMETER, 21 TOOTH, AOD, PURPLE MUSTANG
 

93tealstang

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Jan 24, 2002
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McSherrystown/Hanover Pennsylvania
Apr 17, 2009
#7
  • Apr 17, 2009
  • #7
The 23 tooth you have will fit but not like it's supposed to. Never heard of one that didn't fit at all like your describing.
 
T

Twistedimage

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St. Louis
Apr 17, 2009
#8
  • Apr 17, 2009
  • #8
93tealstang said:
The 23 tooth you have will fit but not like it's supposed to. Never heard of one that didn't fit at all like your describing.
Click to expand...

Maybe i didnt put it on right ill try again today, thanks for all your help.
 

Beasty306GT

Active Member
Dec 19, 2002
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Oxford,Mass
Apr 17, 2009
#9
  • Apr 17, 2009
  • #9
you need the 21 tooth purple gear...23 tooth is for 4.10 gears
 

dcurtis

10 Year Member
Jan 19, 2006
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Apr 17, 2009
#10
  • Apr 17, 2009
  • #10
Thats the same gear I installed after my gear swap, I did have to make the slots for the clip a tad bit wider for it to fit. I have a 91 Gt with the aod, is there any way to tell what year the tranny is from? The previous owner replaced the tranny in my car just before I bought it, so I don't know that I have the correct gear.
 

93tealstang

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McSherrystown/Hanover Pennsylvania
Apr 17, 2009
#11
  • Apr 17, 2009
  • #11
SickSix said:
you need the 21 tooth purple gear...23 tooth is for 4.10 gears
Click to expand...

The white gear will get the speedo semi-close with 3.73 or 4:10's.
 
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Twistedimage

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Apr 12, 2009
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St. Louis
Apr 19, 2009
#12
  • Apr 19, 2009
  • #12
Ok i tried for 30 mins yesterday trying to get the damn gear on. it seems like its 1 mm to short so the stupid pin wont fit am i supposed to do anything else to get it on??
 

jrichker

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#13
  • Apr 19, 2009
  • #13
The stock range of speedo gears work correctly with a limited range of tire sizes. The 23 tooth white gear works good for some guys, but self destructs in a few months for others.

See Gear Ratio Calc for more help

Check to see if there is a speedometer shop in your area. If there is, ask about the Stewart-Warner speedometer gearbox. I believe it is either a 777 Series Drive Joint Kits and Parts or 666 Series Drive Joint Kits and Parts. It is a small gear box that fits between the speedo pickup gear on the transmission and the speedometer. It has quick change gears that allow you to choose almost any tire size and rear end gear ratio you want. This will allow you to get the accuracy within 1%-3%. The drawback is that it isn't cheap.

Please excuse the typo (theirs, not mine) in the following picture - it should read Custom ratio adapters, not Custom radio adapters.

See Speed Correction Devices (Ratio Adapters) for more info.
 
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