Speedo Issue

[Sjepps]

So... speedo doesn't work. Actually I'm not sure the dash gauges are working at all. Fuel stays stuck on full all the time, maybe that's normal?

Anyway, previously owner stated that speedo would work if the cable was slightly unscrewed at the transmission connection, but it would then leak fluid out.

Anyone have thoughts? I haven't gotten under there to look aside from changing fluids out so far.

[cny first gen 71]

Possibly the inside cable is to long causing it to bind up aftermarket parts may not be exact,  check the power and ground on gas Guage. 

[cbolt]

What about the other gauges? The speedo is mechanical and the other gauges are electrical so those issues will not be related. From what I understand, the part of the transmission where the speedo cable is connected does not normally have fluid and should be fairly dry all the time. (minimal fluid at the most) Like Steve said, the cable may be incorrect for the application or just worn at the transmission end. 

[Dtret]

Or not correctly popped into the speedometer. 

[DragCat]

2 hours ago, cny first gen 71 said:

 check the power and ground on gas Guage. 

this, a ground will cause the gauge to peg. 

[stangeba]

Here is a picture of my 71 Speedo connection at the instrument cluster with the cable assembly removed.

The "clip" (bottom) is what holds the cable to the speedo. Make sure the cable assembly is fully pushed into the speedo.

I remember one time my plastic gear, at the transmission end of the cable, was all worn out and needed to be replaced.

You could jack up the car, unhook the cable at the transmission, verify the gear is not worn out or missing, then spin it with a drill mtr while someone is watching the speedo to see if it works. I don't know if spinning it with your fingers is fast enough but you could try.

I remember having lots of fun when I added cruise control to my 71 years ago, WOW!!

[cbolt]

16 hours ago, Sjepps said:

 

Anyway, previously owner stated that speedo would work if the cable was slightly unscrewed at the transmission connection, but it would then leak fluid out.

 

Makes it sound like the issue is at the transmission end, but thinking about this a little more I would say you definitely want to verify whether or not this is true. Just because the previous owner says something doesn't actually mean its accurate. 

[Sjepps]

Thanks for the responses guys. I'll put it on the lift and check everything when I can.

[Scott S.]

The cable ends might also be rounded off.... I've seen that happen if the cable was binding. 

They are just made of plastic, and if original, over 50 years old.