My speedometer needle is the only item on my instrument cluster acting amiss. The car is running fine, tach and temp all working normally, but speedometer needle randomly works, and can be willed into working with some random smacks to the dashboard above it. What am I dealing with here? The gear in the needle? The connector running to it? How do you fix JUST the speedo needle?
You are going to have to dig in and get to it physically. Especially since you say you can get it working by physical persuasion. By being able to touch it you will better understand why it's binding or there is a bad connection.