Problem With Bionicle Joint Sockets Cracking, Repair Options?
The socket joints from around 2008-2010 were poorly designed. They were both too thin and too tight, so cracking was a very common problem.

Because the issue is the shape of the part, super glue doesn't do much. I tested it out on of my broken joints and the parts cracked again the first time I connected it. So don't bother with that.

What may help is sanding the inside of the socket's prongs down to make it less tight during insertion. I tested this out on a few of my sockets. Sanded sockets took 100 insertions without cracking while the ones that weren't broke after 20-30. However, I've also heard that the 2008 joints crack after sitting too long in a connected state, which sanding may not prevent.