.....Speedomter cable. I have a 48 f-1. Purchased a speedometer cable from one of the larger part houses and for the life of me I couldnt get it to work. Found out from the mechanic that the male end going into the female in the speedometer was too big to go in all the way and have the coupling screw in. (This is not x rated by the way). SO the end of the story is the part houses must have the wrong size cable for the truck...word of warning

 

I have the same problem with a cable I bought from an outfit in OK. Did your mechanic indicate if the problem is diameter or length of the stub? This one seemed to be too long.....

 

The problem was in the diameter. It took him awhile to figure it out as well. The cable goes in but just not in all the way for the coupling to fit tightly.

But the good news is he found one and the speedometer works as good as usual. I can be going 10 or 15 and it shows nothing for a second and then pops right up there. Admittedly these speedometers are not the best but they give you a fairly good idea of how fast one is going. I got it up to 50! Wow...speeding.....