Speedometer refuses to work. Any help is appreciated

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projectmidnight74

projectmidnight74

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So at this point, the original th350 has been rebuilt, I have put a new speedo cable in as well as a speedo bullet because it was leaking. I still have 0 mph when driving. Any help is appreciated otherwise, Im just going digital everything soon lol.
 
PrairieDrifter

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projectmidnight74 said:
So at this point, the original th350 has been rebuilt, I have put a new speedo cable in as well as a speedo bullet because it was leaking. I still have 0 mph when driving. Any help is appreciated otherwise, Im just going digital everything soon lol.
Click to expand...
Either something wrong with the mechanism in the gauge or the input is slopped out on the gauge. Did you look at the drive gear on the transmission output?
 
projectmidnight74

projectmidnight74

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Yes. It looked to be fine. But again I'm a novice at this lol. I have a yellow one I bought new. But didn't out it in. May have to just got digital.
 
PrairieDrifter

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projectmidnight74 said:
Yes. It looked to be fine. But again I'm a novice at this lol. I have a yellow one I bought new. But didn't out it in. May have to just got digital.
Click to expand...
Have you checked if the cable spin at the gauge end?
 
75gmck25

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You should be able use a drill to spin the transmission end, and it will make the speedometer read. If that works, then it’s the transmission connection you need to work on.
 
PrairieDrifter

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projectmidnight74 said:
Its brand new. No way its bad right. I guess I need to check.
Click to expand...
Even if brand new, doesn't mean it's good. But it also means you could have not got everything together just right.
 
Matt69olds

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Is the drive gear in the output shaft?

Raise and properly support the rear of the truck so the termites are free to turn. Disconnect the speedo cable, put the shifter on neutral. Spin the driveshaft by had, make sure the driven speedo gear turns.

If not, you need to figure out why.

There are different speedo housings depending on gear. As the speedo gear count goes up, the gear gets bigger, the housing has the hole offset to accommodate the larger diameter.
 
Rusty Nail

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75gmck25 said:
You should be able use a drill to spin the transmission end, and it will make the speedometer read.
Click to expand...
That's all the good help I had ...chuck it in a drill. :rockit:bet that mother humper gon spin now aint it??
Dontcha know!
 
projectmidnight74

projectmidnight74

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all I have are impact drills lol. any plan b to turn this sum gunn lol. Recap.
New speedo cable
new bullet
same gear with a new yellow one on standby.
 
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Under the hood locate the speedo cable and push it into the cab. You may just get lucky.
 
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borrelemily7

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inside the transmission is the speedometer gear drive. it is a plastic pieces with teeth. different transmissions call for different number of teeth. it is pretty simple to remove. check it. mine was a mechanic shop and while there it disappeared??????? I am just having trouble finding the correct number of teeth that my 78 C10 requires.
 
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