speedo needle jumps at any speed sometimes as much as 10 mph is it a bent cable or am i missing teeth on a gear any one know

 

it might just need to be lubed. I would disconnect it from the transmission, and chuck the end up in a drill and spin it, I think you need to run the drill in reverse, and see if the speedo still jumps around. If it doesn't then you know you problem is in the trans.

 

If that jumping just started to occur, then lubing the cable might help it...for a while. But, most likely, the cable is wearing an area of the sheath interior away and smearing the residue around, causing the cable to bind as it rotates.

If you decide to lube it, you have to remove the cable end from the speedo housing (driver's dash area); then you can pul the cable out from the jacket (you can't do that from the other end). To lube it, use a dry graphite powder; put some in an area of a [relatively] clean cloth and drag the cable through it. After it runs through that lube, it should feed through another area of that cloth so that it wipes excess lube off. You want a film of graphit lube on the cable...not a bunch of it. Also, you should not put lube on the last 1-2 feet of the cable (at the speedo end). The direction of the wound wire on that cable will act as a 'corkscrew' when it rotates and tend to "pump" any excess lube up toward the speedo head. If it gets into that speedo mechanism, it will contaminate it and cause it to fail [eventually].

But, it's worth a try. However, if you again start having trouble with it, you should replace the cable/jacket completely. And, when you install it, try to minimize bending and make any bends as large as possible.