Please bear with me. I searched and researched and nothing quite hit on this issue.

Had all dash and gauges out of car all redone and bench tested.

Installed everything loosely to retest all new bulbs connections etc.

Driver's side dash properly in place but just sitting there for testing.

Here is the problem:

1) Brand new refurb OEM speedo. Bench tested works great.

2) Speedo cable ( properly lubed) properly seated in clip on back of speedo.

3) attached properly down at manually tranny.

4) Slowly put in gear on lift and lightly throttled up a tiny bit. No reaction on speedo.

5) Unhooked speedo at tranny and hooked up to drill. Drill in reverse activated and speedo moved accordingly, so the speedo and cable function properly.

Once it is back hooked up on tranny nothing on speedo except a brief flicker.

I called my mechanic father in Florida and he mentioned that sometimes new cables are just a hair short, and therefore not engaging properly.

He suggested pulling the cable from the sheath ( dicking around with dash stuff again!!!!) attaching to a vice at one end and gently pulling to put a little stretch in it.

I'm not one to doubt a mechanic, albeit my father ( jack man for Nascar Rookie of the Earl Ross in 1975) but..............

I am looking for any comments / advice / suggestions before I go down this road.

 

Ttt......................

 

Could the gear in the transmission be worn out?

 

Sounds to me like the drive gear in the trans might be the culprit. Not sure, but have a look inside where the cable sets in the gear. It might be worn and not spinning the cable??

Pete...ya beat me to it!!!

 

If you have a 90* adapter there is a small shank, about 1/16" square and about 1" long, in some of them that will fall out and without it, the speedo. will not work.
I had one in mine and it fell out when I went to install it. I put a small dab of greese on it to hold it in place.