Speedo trouble shooting

[ChryslerCaptain]

Hello All i Hope someone could point me in the right direction I have a 72 Imperial that I’m restoring and the speedo/odometer does not work I’ve tested both cables the one going from the trans to the cruise control unit and then the one from cruise to cluster both cables move the speedometer when I put a drill on them. but as soon as I hook the cable to the trans nothing works even after verifying that the adapter is in the correct 6 o’clock position. I poped the Speedo gear out of the trans it’s a black 29 tooth gear and there doesn’t appear to be any damage in the transmission or on the gear. If anyone has any advice I’d greatly appreciate it thanks.

 

[CBODY67]

When you power the cable at the transmission end, does the output side of the transducer turn too?

What about the gear on the transmission output shaft? Is it worn? Is it still firmly attached to the output shaft? With the lower cable attached to the transmission, can you turn the cable itself with your fingers?

Just curious,
CBODY67

 

[Big_John]

even after verifying that the adapter is in the correct 6 o’clock position.

I'm not doubting that you verified this, but honestly, it really does sound like that is the problem.

Just to be sure, the "26-31" is at the 6:00 position. This FSM pic shows "32-38" in the 6:00 position.

There is a little free play in the clamp, so you may want to try turning it just a little with the cable off and see if it engages better. I think turning it clockwise(?) would force the speedo gear into the worm gear on the output shaft. Try counterclockwise too.

 

[ChryslerCaptain]

I'm not doubting that you verified this, but honestly, it really does sound like that is the problem.

Just to be sure, the "26-31" is at the 6:00 position. This FSM pic shows "32-38" in the 6:00 position.

There is a little free play in the clamp, so you may want to try turning it just a little with the cable off and see if it engages better. I think turning it clockwise(?) would force the speedo gear into the worm gear on the output shaft. Try counterclockwise too.

View attachment 623401

Yeah it’s in the correct spot. I’ll try your suggestion of slightly turning it.