front end rattle

My 94 4x4 pickup rattles in the front end when I'm braking. I thought it was the wheel bearings, and they were actually loose, so I replaced them. The first time I had to hammer the spindle nuts tight. It still rattled so I got hold of the 54mm socket required to tighten those nuts properly. When I jacked it up the wheels didn't feel loose at all, but I went ahead and torqued the spindle nuts down right. While I was in there, I looked for the rattle and I think it is the cv axle rattling inside the steering knuckle. Is it supposed to have some play? Does it just need some lube or is it broken?