Axle u-joint wouldn't squeak unless you're turning. When the wheel is straight, there is no twisting of bearings, only when turning.
If you're feeling rich, it's a good time to just do it all. If you haven't had them done before, the unit bearings might be a real bugger to get out. We usually end up grabbing the torches and going to town. Start soaking them in the best rust eating penetrating oil you can find. When you put everything back together, a light coat of anti-seize or grease will make the job easier down the road. Don't get the cheap stuff either, I can't tell you how many times we've sent stuff back or had to re-do jobs due to cheap parts.