Hi, I recently bought a used 2008 automatic Subaru Legacy limited 2.5i. We got it checked out by a mechanic, and it seemed fine. But after a few weeks the transmission started to jerk (especially at lower speeds)and it sometimes shakes when braking into idle. We had the transmission checked by 2 different mechanics but they cant find anything and the problem doesn't happen all the time, so they could not duplicate it. Help!
The shaking that you feel may be caused by uneven brake rotors. You may need to have them resurfaced for smoother braking. The "jerking" feeling may be caused by something other than the transmission, could be a vacuum line, or and idle air control valve. If this is intermittent and does not set your check engine light, you may need to have them keep the vehicle over night.