Greetings all, so I'm driving freeway 75-80 with a sudden small loss of power. I decelerated and things seemed ok for the 3 miles to home staying at about 60-65. When I parked tho, loud rattle from undercarriage. I park and realized when I shift gears there is a loud whirring and grinding noise, no reverse. It sounds and feels like like it's trying to grab a gear, smooths out as I continue shifting. Damn! There has been a loud clunking at times when I shift that I think is the u-joint or something in the drive-line, also has been a loud rattle which I've assumed was the heat shields rattling. So, blown cat, diff, gears???? at a loss.