my needle on my speedo wobbles up and down when in use doesn't stay at its correct speed just bounces up and down what causes this

Bad cable
loose angle drive

Lube the cable. If it doesn't help, there is dirt in the magnetic pickup inside the speedometer. Try lubing the speeding input shaft as well.

Some clarification needed.

-What lube should be used?
-What ends to lube? At speedo and/or at angle drive?
-How hard is it to remove the cable at the speedo?

Any oil is fine. Engine oil works well.
It's usually the speedo side that gets dry because its higher.
You literally pull the speedo and unscrew the cable end with your hand. Some electrical contacts may come loose before you notice so pay attention to the colors and locations.

It could be that the cable has broken strands and they are catching and releasing on the cable housing as the cable turns. A sharp kink in the cable will also cause this.

I messed my speedo cable up when yanking on the gauge cluster. Must have pulled and tweeked it too hard or something. It would bounce +/- 10 MPH when under 40.

A new cable fixed it.