I have a major vibration that starts around 45 mph. It's something in the tranny or driveline because it all smooths out if I put it in neutral. I had the center bearing replaced 2 yrs ago. It's hard to tell if the bearing is bad w/o taking out the driveshaft. I'm hoping it's not the tranny. The u-joints look good nothing is loose. I did the rear u-joints last year. When I was under the car I noticed that the overdrive solenoid wire wasn't even attached and the rubber cap on the solenoid was falling apart. Could the solenoid have anything to do with the vibration? The vibration can be felt in the steering wheel, I dont really hear any howling. When I'm over 50 mph it feels like it isnt shifting. What do people think? I plan on pulling the driveshaft to check the center bearing and to ck for u-joint stiffness. Is this tranny or driveline? Any help greatly appreciated. Thanks Phil