ComponY

Alright, so we have a 77 here and are having a problem with the speedometer that we can't figure out.

We replaced speedometer cable that runs from the back of the speedometer, to the transmission.

Then we replaced the cable that went from the back of the speedometer to the box (transducer I believe). Still nothing.

Any tips, tricks, or knowledge? :P

doorgunner

Did you remove the speedometer drive gear in the side of the transmission and check the teeth for stripping?

did you clean out the female end of the drive gear to see if it was still square inside (they can become rounded and will not turn the drive-cable?

Did you drive the car in the driveway to make sure the drive-cable rotated?

Did you make sure the upper end of the drive-cable went fully into the female driven connection on the back of the speedometer.

If all those steps were taken, the internal gear(s) in the speedometer head may be stripped or the grease has hardened to the point that the head cannot function properly....

(whew!)

Raphiki

That autta do it!

red topless gator

My guess is to check the nylon gear in the transmission. Doesn't take much for these to go bad. What ever you do, be careful when removing or replacing that gear., It can fall into the transmission, ask me how I know.

JimLentz

Sounds like a problem with the cruise control transducer. These are a known problem. If so, you can bypass it with a single, longer speedometer cable.

Giant_Robot

77 here, just fixed mine with a new gear in the trans.
probably the same issue, swap/check this before you waste money and buy a new cruise transducer to 'check' that...

ComponY

Do you have to extract the trans and everything to do that? Such as open it up and get into depth?

Giant_Robot

nope

ComponY

Seems like the actual speedometer gear was broken, so we'll be replacing that and see where it goes from there. Hopefully it works.