Just as Vermsta said you should check it multiple times as the fluid level will drop after things are apart and definately check it again after a road test to verify it is full. If it is low again then I would suspect it leaking somewhere OR check your coolant overflow tank. This sounds odd but a customer of mine ran into this last year. His radiator was bad and trans fluid pumped into the radiator to the point where it was blowing out the top of the coolant over tank and leaking over the passanger side axle! Just keep an eye on the fluid level, not sure what to say about the other noise you hear. Does it make the noise at all sitting still in P, N or D? or just driving down the road and coasting?
