2003 yukon has a rebuilt 4l60e that previous owner put in. It had 40k on it when I bought it, and I've out on 55k on it since. It has always had a whine that owner said it had since replacement. It also has a bit of a slip to it. What fluid should I use? How much? What filter should I use? Should I put a quart of Lucas Fix All to it to aid in slip?