Problems with humming sound

They should have a print out on the alignment. But unless it is eating tires I'm not sure I would replace it. What did they quote to replace it? A new beam is about $600.00 for the bare beam.

I wouldn't, If you get a chance take a close picture of the tires that were on the rear and post them. If there is weird tire wear it may show up, but unless it's way out replacing a set of tires every 20-30 thousand might be cheaper. You could also take it to one of the chain stores that does alignments and rotations cheap and get a printout on it's current condition. Here there are places that do them for about $50.00 and that would give you a better idea of the problem, unless they give you a print out, if they do post it and we can look at what it might do if it's bad.

Yep, just log in and it will still be here, forever, or at least until the internet finally crashes.