If you have the cluster out, have the tech run the speedo up slowly with a vatiable speed reversible drill and a cable stud. If the movement in the speedo head is sticking, this will give it away, otherwise, it's probably your cable or cable housing. How long ago did it start doing this and did it start suddenly??
1987 BMW 325
[This message has been edited by jeffsr (edited 04-10-2000).]