My speedo is working only intermittently.  Cold mornings seem to be the worst.  When it's not working there's a noise coming from the transmission tunnel - presumably it's the cable's attachment at the tranny.  Any thoughts?  I would think if something was physically broken down there the speedo would never work, not intermittently work.  I've not had a chance to put it up in the air to take a look - maybe it will be obvious once I do so?  

They need to be relubed regularly. Disconnect at the tranny, remove the inner cable, use special lube, slide it back in.

Thanks guys.  No CC in '76 so my cable is one piece.  I replaced it when I did the engine a few years ago - probably not much more than 1K miles on it.  So I'm concerned it's more of an installation problem than a wear problem.  I think I'm just gonna have to get it up in the air so I can figure what's going on.  I got tangled up doing a rear brake job on my suburban (drums, ugh) this weekend so I ran out of time.  Will keep you posted...

Yer prolly on the right track with that idea. If the ferrel for the cable is loose where it connects to the speedo adapter, OR the speedo adapter itself is loose, it can cause those exact issues...noise, and erratic speedo. Being a 4 sped car, it should have the 90deg adapter/ratio corrector on it right out of the trans, and the cable attaches to the adapter. Yer gunna hafta crawl under there and have a look....

Thanks, Joel.  Yep, gotta do an oil change anyway so it'll be up on the ramps or jack stands in the near future and I'll check it out.  'cept now you have me worried - I'm not sure I remember there being a 90 degree adapter on the tranny for it.  If not, maybe that's my problem.  

It will look like dis un, if ya has it. MOST 4 speeds used the adapter, but it might depends on what rear end ratio the car has.