Question - DIY Becket Noise

[Todd]

I recently purchased a DIY becket skimmer from a local reefer. It is a PM Bullet knock off (Sized between a bullet 1 and a bullet 2). The becket is housed inside of a pvc pipe. I have taken it apart a few times to clean it (I don't yet have a screen on the pump, thus any little thing gets into the becket and slows it down), and about 2 / 3 times when I put it back together and turn it on, I get a very loud clicking noise. I can feel the becket rattling inside the pipe. I usually end up taking it apart and trying to put it back together so that it is quiet, but I don't know why it makes the noise and how to put it together so that it is quiet. Any help?