Speedo Wont read about 85mph...

onefstsnake

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Nov 25, 2005

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Northern VA

Jan 20, 2006

#1

• Jan 20, 2006

• #1

Speedo Wont read above 85mph...

I have a 140mph speedo. Standard in 93...

Well once the car gets to about 80-90mph the speedo just drops to 0...
After I let off I hear a tapping sound. The taps arent random but in a patern.

Is my speedo gear going bad and thats what the tapping sound is?

How hard is it to get to the gear? Just want to get this taken care of.

Thanks.

 

P

plainwrecknate

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Jul 21, 2005

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Fort Morgan, CO

Jan 20, 2006

#2

• Jan 20, 2006

• #2

I have a similar problem, after about 65 my speedo starts jumping around between 60 and 90. We lubed the gear, replaced the cable, still happened. There's a tapping noise on mine too. Find out where the tapping is coming from... Mine is coming from the speedometer housing itself, so you may need a new one, like me.

 

onefstsnake

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#3

• Jan 20, 2006

• #3

my tapping sound is coming from the transmission or somewhere around there.

doesnt seem to affect anything, but it doesnt sound good.

 

5.0 Nostalgia

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#4

• Jan 20, 2006

• #4

Did you take out your speedo gear and see if the teeth are cracked?

 

onefstsnake

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• Jan 20, 2006

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not yet. Ill try to look at that today.

 

Euphoric306

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#6

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nate, your magnets are worn in your speedometer in teh 65, that's why it's jumping. yes. you need a new speedometer.

 

onefstsnake

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#7

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turns out the gear is fine.

Its a black gear... I havent seen a black gear before unless its an OEM or something.

The metal piece that the gear slides onto is all messed up.

Just going to order a whole new sensor and gear.

I take it I will need a White 23t gear?

This is the part thats broken.

 

5.0 Nostalgia

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#8

• Jan 20, 2006

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That's the Speed Sensor. I got one at the local Ford dealer for $35. Unless the gear is broken, you can just put it back on the sensor.

 

onefstsnake

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#9

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Im ordering it from 50Resto for $22

I have 4.10 gears so I need a different gear to make the speedo accurate.

 

larrendeuce

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Sep 13, 2003

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Southern NJ

Jan 20, 2006

#10

• Jan 20, 2006

• #10

I don't know what transmission you have, but the gear for my AOD was black. It has the correct 23 teeth, but the gear is not white. I have an 8 tooth drive gear with the 23 tooth driven gear. Its supposed to be close for 3.55 gears. I have 3.73's and its 5 mph too fast.

 

onefstsnake

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#11

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maybe I have 3.73's then.
b/c mine is just about 5mph fast.
The guy I bought the car from didnt know what gears were in it...

Just ordered the sensor and some 50resto stickers.

BTW I have a T5

 

5.0 Nostalgia

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Jan 21, 2006

#12

• Jan 21, 2006

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That's correct. The AOD gears are a different color than the T5 gears. The shaft on the AOD gears are a little longer too.

With 3.73's or greater, you can't get the speedo 100% accurate without replacing the drive gear. For more info on speedo gears try this thread:

http://forums.stangnet.com/showthread.php?t=608790

 

onefstsnake

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#13

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so why do I have a black gear on a T5?

Should I replace it?

 

5.0 Nostalgia

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#14

• Jan 21, 2006

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I don't know why you have a black speedometer gear. Can you pull it off and take a picture of it? Maybe it's the auto gear. Was your car ever an automatic?

 

larrendeuce

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#15

• Jan 21, 2006

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count the teeth

 

onefstsnake

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#16

• Jan 22, 2006

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5.0 Nostalgia said:

Was your car ever an automatic?

Click to expand...

Nope, car is 99% original/stock.

Well the sensor used to work just read 5mph high.

The little grooves on the sensor were bent/broken causing the speedo gear to move in the tranny.

You dont think it could be the gear in the tranny case do you?

 

5.0 Nostalgia

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#17

• Jan 22, 2006

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I don't think it's the gear in the tranmission. I guess it's possible, but not likely. Best thing to do it slow down! But really, all the speedometer's are inaccurate above 80mph, even the calibrated ones. I remember reading a couple months back about a cop on here who used to drive a 5.0 police car with the certified calibrated speedometer. He said above 80 mph, it read high.

 

onefstsnake

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Jan 22, 2006

#18

• Jan 22, 2006

• #18

My speedo is 5mph off at all speeds.

When Im doing 35mph it reads 40mph.

but now it reads 0mph all the time.