torn gearbox boot,clunking and a small battery question

I have an 85 1.8L 4WD non-turbo wagon. My gearbox boot is totally torn. The CVJ and DOJ boots both look good. I get a clunking sound when I turn to the left. Related? Also, this gearbox boot has been torn for a long time. Are the ball joints ruined and is it easier to replace the whole darn assembly or should I try to replace the ball joints alone?

Last question is easy.... I took the clamp-down bracket off the battery, and now I can figure what the heck the little hook at the bottom hooks on. All I can find is the plastic tray the battery sits on. Then below that there is nothing to clamp to. I had a honda where the battery sat on a shelf, and you clamped the battery to the bottom of that shelf, but that is evedently not the case here......