97 Legacy L 2.2L AT, and when I go over 40mph, the speedometer goes nuts and there's a loud squeal under the hood. Tach is fine. Noise slows down when I slow down, regardless of RPMs. Automatic tranny shifts fine. When I get down to 5mph, the noise stops and doesn't start until I go somewhere over 30. Noise started after I hit a pothole, which may or may not be important. Other detail is the Speedometer, which bounces around for a few minutes and then goes all the way to the right of the gauge and stays there until I slow down to a stop. Any ideas?? Drive belts are new and seem tight enough. Thanks guys.

Edited March 8, 200917 yr by erikvr

Your speedo cable probably needs to be greased, or the speedo cable base is on its way out, and needs to be replaced.

 

http://www.main.experiencetherave.com/subaru/images/speedocablebase.jpg

I have to regrease it every year:

http://www.ultimatesubaru.org/forum/showthread.php?t=71564

 

only a 15 minute job