engine shake

Hey guys, This is my first post here so bare with me. I have a 91 Lesabre Limited, I've taken care of her since I got her a couple years ago and last week I randomly started getting a weird idle. It seems to be normal in park and neutral but once it's in gear it idles way down and shakes the...

Hi, This one has me stumped. If cruising at 50-55 around 1500rpm if you start up a hill the engine/tranny begins to shake violently. If you let off throttle it quits, If you put your foot into it it quits, but if you are still climbing and let rpms back to just above idle it will start shaking...