Chair leaning to the right

So I've had this chair for about 5 or 6 years now. I love it but it's leaning to the right when I sit on it. I can lean it to the left and hear a popping noise and it will lean to the middle until I lean to far right on it and hear the popping noise again and then it leans like 3 inches to the right. Not sure what the issue is. I don't want to have to buy a new chair it's still as comfortable as the day I bought it and I love it still. It raises and lowers with no issues but when I flip it over I can't see the issue. Do you think the chairs just dead or can it be fixed? Also seems like the chair is discontinued. I think it was the racing series.