First Problem: The transmission shifts hard making a bang and jerking feeling. This doesn't happen all the time, I would estimate it to be about 50% of the time. I have heard about stories when people getting their transmission worked and and within a short duration they were stranded on the road because the recent repaired has failed. The transmission can be pretty annoying at times but it haven't broke down on me yet. I don't want to take it in to the dealer on Monday and have it break down shortly after getting it back. There is no check engine light on or anything. Does the dealer connect the explorer to a machine to check for this problem or do they take it out for a test drive? Should I move forward with the appt. on Monday or should I cancel it? Second Problem: There is a vibration with the vehicle. I don't feel the vibration while the vehicle is moving but when in park idling, in drive stopped at a light or etc, you can feel it. Feels similar to a massaging chair. I was guessing either the engine mounts or the harmonic balancer. Information: 04, v6 engine, 4wd Thanks in advance for the advice and help.