Help, when accelerating from a stop, especially when cold, 2001 Lesabre, sometimes shudders the whole car andchirps the front tires then it stops and goes on its way normally. It seems to be random, but usually happens when giving gas quickly from a stop, especially going up a hill. I also noticed it a few times when changing gears to pass someone, again usually when pressing on the gas pedal abruptly, but most of the time it behaves perfectly normal. It has 58K miles. Does this sound like a trans. problem, or is it something else? Trans fluid looks perfectly clean and just slightly below the top level. Thanks.