How can I tell if my torque converter seals are blown and are they replacable?

Engine is 5.0 automatic. When I put the vehicle in reverse it chugs/sputters. I was told if I put it in neutral gear with my foot off the brake and then put it in reverse it will chug/sputter or if I roll it backward downhill in neutral and put it in reverse it will chug/sputter if the torque converter seals are blown. The vehicle drives fine in other gears.