Speedo issues

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Sep 3, 2021 | 05:23 AM

Tbanks1382

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Speedo issues

Speedometer in my 1985 F250 hasn’t worked since I bought it. I unplugged the end out of the transmission and when spun in the chuck of my cordless drill the needle moves. The plastic gear on the end of the cable appears to be in good shape. Obviously there is an issue with it mating inside the transmission any ideas on a remedy?

Sep 3, 2021 | 05:53 AM

Franklin2

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From: Virginia

What transmission? Or does it go in a transfer case? What kind of transfer case? Most but not all, you can pull the tailshaft housing off and get access to that drive gear.

Sep 3, 2021 | 06:30 AM

Tbanks1382

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I’m not sure which transmission. It’s a 4 speed manual. The Speedo cable plugs into the back of the transmission itself.

Sep 3, 2021 | 10:38 AM

Franklin2

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From: Virginia

Here's a old thread with some info on getting the gear. Since you have a f250, you could have the np435, or a t18 or t19 transmission.

https://www.ford-trucks.com/forums/7...rive-gear.html

Here's a link that might help in identifying what you have. If you have a 460 engine, you most certainly have a t19 but double check to make sure.

Sep 4, 2021 | 11:55 AM

FuzzFace2

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From: Angier, NC

Just to let you know it dose not take much wear on either gear to cause issues.
I had a T18, granny first gear 4sp, that I had to replace both the cable end gear (driven gear) and the gear on the output shaft (drive gear) to get my speedo to work.
Because the T18 was bad a swapped in a NP435 using the same driven gear and it did not work.
In checking the drive gear it showed a little wear so I swapped it for the T18, yep both use the same drive gears, and it worked again.
So a little wear can cause issues.
Dave ----

Sep 9, 2021 | 10:00 PM

Station25

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From: WI

Inside tailshaft of trans is another plastic gear. Poke your finger inside of it. I'll bet you feel a worn down grove in the center of it...also try to spin it. Shouldn't move.