missing speedometer drive shaft gear

enginewolf

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I have a 1973 mustang coupe hardtop that I picked up in March,2015 it has a 351w from a 1994 ford lightning that has been converted to carburetor. Still alot of work to do to it. Looking for help understanding this old ponny
Hey everyone, I have a 1973 coupe that I'm trying to get all the kinks out. What I'm having an issue with now is my speedometer doesn't work. I've checked the cable and it is still working. I can turn one end and guage responds but when I plug it into my tranny and drive the guage reads 0. I looked into the hole when the cable goes in the tranny and I do not see anything but a smooth shaft. I'm under the impression there should be a gear there that turns the speedo cable gear correct?

DSC_0024.JPG

 

c9zx

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The drive gear does appear to be missing. Remove the tail shaft housing to confirm. Chuck

 

MeZapU

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There should be a drive gear in there. What type of transmission is it?

 

enginewolf

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I have a 1973 mustang coupe hardtop that I picked up in March,2015 it has a 351w from a 1994 ford lightning that has been converted to carburetor. Still alot of work to do to it. Looking for help understanding this old ponny
Sorry. It was stated to me that the tranny was a c4. Since I haven't had the car to long I haven't verified If that's true. But for sake of argument say it's a c4, is the gear supposed to be pressed on? I know some are pressed and some are held on with a type of clips believe.

 
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trillizo_y_uno

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The gear is held on by a snap ring. There is also a small ball bearing that holds the gear in place which keeps it from spinning on the shaft. It is real easy to replace once you have the tailshaft removed. Since your gear is missing completely, I'm guessing the snap ring and bearing are missing as well.

 

enginewolf

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I have a 1973 mustang coupe hardtop that I picked up in March,2015 it has a 351w from a 1994 ford lightning that has been converted to carburetor. Still alot of work to do to it. Looking for help understanding this old ponny
10-4 thanks alot. I'll start to tackle that job today

 

enginewolf

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I have a 1973 mustang coupe hardtop that I picked up in March,2015 it has a 351w from a 1994 ford lightning that has been converted to carburetor. Still alot of work to do to it. Looking for help understanding this old ponny
So Ive started on the job and I have found out I have a 1977 C6 transmission and not a c4 transmission like originally state. and the drive shaft is bare no drive gear anywhere to be found.

DSC_0028.JPG

 
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MeZapU

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Kudos for tackling it yourself so quickly. If it weer me I'd stop by a transmission shop. They are likely to have some core transmissions or parts in their bins to get you what you need. Or they can refer you to the correct part source with a part number to order.

 

enginewolf

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I have a 1973 mustang coupe hardtop that I picked up in March,2015 it has a 351w from a 1994 ford lightning that has been converted to carburetor. Still alot of work to do to it. Looking for help understanding this old ponny
Thanks for the website but I don't have a 4 speed, it's a 3 speed automatic

 

computercarguy

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It's a good time to know your axle ratio and tire size to get the correct gear for your speedometer to be accurate.

 

enginewolf

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I have a 1973 mustang coupe hardtop that I picked up in March,2015 it has a 351w from a 1994 ford lightning that has been converted to carburetor. Still alot of work to do to it. Looking for help understanding this old ponny
Has 2.8 rear end and 265 r15s I didn't think that stuff mattered for the drive gear that goes onto the output shaft. I thought that info was needed for the correct speedo driven gear.


I'm starting to believe it was supposed to have a metal drive gear cut into the shaft itself honestly. Just not sure why it wouldn't have it then.

 
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c9zx

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Thanks for the website but I don't have a 4 speed, it's a 3 speed automatic
Sorry about the brain fart. I guess I'm four speed obsessed this week, putting a clutch in my other car. Chuck

 
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