Have a non working 150 speedo in my '73 Charger, cable is not connected under dash account broken plastic coupler. Pulled old cable and also noticed covering twisted and torn about a foot from the tranny. Replaced with new lubricated cable, all connections good and now needle jumps to 50 as soon as I move forward and then to 100, back to 50, up to 100 and so on. Does this sound like the speedo is trashed?

Often times an old cable will be to blame. The "permanant lubricant" has dried or leaked out and the actual inner cable that drives the speedometer binds, then releases, then binds, etc. You can try squirting some silicone lube into the cable, or open the wallet fot a repop.

When you say "Replaced with new lubricated cable" do you mean you replaced the entire cable assembly or only the cable core?

The entire assembly.

The good news is that they are still avaiable through Mopar parts.
Craig

I had a brand new cable and housing I purchased off of ebay from a "quality" vendor.. Maybe it was my fault letting it get too close to the exhaust, but the needle bounced around until about 40mph from the first day I drove it.. I had redline build me a quality cable and housing, made sure it was away from exhaust and it works perfectly.. It has a metal housing and no more problems...