I hear ya. It is highly suspect when one alters one, or more, things and a strange result happens. It has happened to me as well. On a 70 Lemans Sport, I replaced a cracked torque converter cover and the same type of noise was heard instantly. that was the only differance which was done to the car. I put on the old one, the noise was gone. Turned out the cover was not a good casting. Point is...if you have changed something and a noise has started, it is a good chance that you did NOT put it back together exactly as it was previously. When u-joints USUALLY go out, one puts a vehicle into reverse, we here a clink as the slop slaps the drive shaft to a quick stop. Now saying it's not a possibility. We all, from time to time, don't assemble things properly and have to redo. Today, for instance, I replaced a ball screw on a waterjet. I forgot to put the dampener in on the end, a 10 minute mistake. No big whoop. I would go through and double check all I had done to be doubley sure.