99 z28 a4 At idle there is a grinding noise coming from the floor board. If you put your ear to the floor in the area where the heater duct is it sound like grinding brakes when they are metal to metal. It’s very noisy when you are going very slow or in reverse and seams to get worse as the car warms up. Also under moderate acceleration about 50 % throttle I get a bad shutter or vibration just before the Trans shifts from 2nd to 3rd. You can feel it through out the entire car but as soon as it shifts gear it goes away. If you hold it in 1st gear and run it up I do not feel the vibration. But if you rev up the car slowly in park I get a bad shutter or vibration at around 2500 to 2700 rpm it seams to go away a little over that. Any ideas what might be wrong. The Trans seams to shift hard and I can get good rubber when it shifts from 1st to 2nd no codes either. Shift time and pressure adjusted with Predator (time -15% - pressure + 15% each gear) Thanks Rick