Is it normal for an Achilles tendon to crack?

I've tried to do some research, but none of it has really answered this. Every once in a while, maybe once or twice a month, my rick ankle will get this almighty pain, and in order for it to go away, I have to move it around so it can crack. (The pain is in the very back of my ankle. I believe it's my achilles tendon.) It hurts to move it, and it even hurts more when it cracks. I'll have to do it three or four times for it to go back to normal. When it starts to hurt, it feels like a stabbing pain and I'll have to grab onto something in order to keep myself up. Could this be because of my weight? I am overweight, so I'm possibly thinking that could be one of the reasons. It's been going on for over a year. I'm not sure if something is wrong with it, or it's just a regular thing.