Speedo Cable

Hey guys, ok heres my problem. My speedometer bounces around pretty good in my "A" body from 10mph up to about 30 mph then smooths out. I was thinking about replacing the whole thing from the tranny to the dash. I was told that if I was to unscrew the speedo from the tranny that I would be able to pull the speedo cable out from the casing, clean the cable up and then when re-inserting it add a little white grease or even graphite to allow for the cable to turn freely. He said this would eliminate the bouncing speedo needle. Has anyone ever done this? or can this be done? He said he done it in his Chevelle and it corrected the bouncing speedometer....
Thanx
Author: admin