Subaru Repair: 1999 Subaru Brighton Wagon Speedometer, rear hatch, speedometer

Question
Wondering what I should look at to repair a intermittent speedometer. It will work for weeks then go dead for 5-10 miles and then be fine again. It seems that slamming the rear hatch can cause it not to work for a few minutes. Looking for some pointers or advice.

Answer
Common for the '99 legacy to have speedo problems. The speedometer head needs to be replaced. The bad part is when replacing this it also replaces the odometer, and will make the vehicle TMU (true milage unknown), and will hurt the resale value of the car.