What's the clunking noise??

Hey everyone. I put a supposedly rebuilt 489 center section in my 8.75 rear axle a couple of years back. Bought it at an estate sale. Gentleman who owned at had passed away. It has a limited slip but I can't remember if it's clutch or cone type. I get a loud clunking/ popping or ratcheting sound when I turn left from time to time. Doesn't make the noise if I coast through a left turn or if I've got some gas applied. Only seems to do it under part power or if I try to accelerate from a stop when I turn left. No other noises while driving. At first I thought it was because it was new but I've got a couple thousand miles on it now. Is this thing eating itself? Any suggestions? Thanks in advance.