1995 Nissan Truck won't start - suspected battery terminal

When I turned the key to start the engine, it made a grinding sound. Eventually after enough tries, the engine would start. I had the starter replaced, thinking that this was the problem. After the starter was replaced, it still made the same sound. (The mechanic did ask me, in a confused fashion, why I was replacing the starter. As if he was saying the starter looked fine. I should also add that I had the starter previously replaced at 90,000 miles.) A week later and some more grinding sound, it plain would not start at all. No sounds, nothing. The instrument lights come on, as you would expect. But the engine does not turn over at all. I pulled the cables off the battery and removed all corrosion and grit to provide optimal connection to the battery. I hooked up the cables again and the car started up! I thought the problem was fixed. After a day of driving, the engine would not turn over. After looking at the battery terminals again, I noticed that the negative cable was rather loosely fitting over the negative terminal. Thinking that it is this loose connection that is causing the intermittent starting, I tightened down the cable as much as possible. Even so, the negative clamp seems to be out of threads (probably due to corrosion) and thus I can’t tighten it down to provide full 100% contact. So I used aluminum foil to try and provide full contact and take up the slack. Still the engine will not turn over. I believe it is the negative cable, but I am not sure.