I know this is a Monte Carlo forum but I figure there must be someone here who can help. I have a 2005 Pontiac G6, it has 100k miles on it and we have been having alot of issues with the front end. Our warranty is now up and the front is needs work yet again. At highway speeds the car wobbles real bad especially going around turns. It's not like a bad balance on the tire wobble. It feels like the front end is going to drop. Also when turning the wheel I can hear the front end squeak which to me sounds like bad ball joints but my 96' Mustang had bad ball joints and it doesn't sound the same.

Now I took a look under the car and saw this on both the driver and passenger side near the wheel hub if this isn't the wheel hub.

 

Given how a bolt travels through that, I wanna say that "split" in the casting looks normal (unless I am missing something else in your pic). As for the dust boot on the ball joint being squished, that is normal.

Based on your description, I am suspecting a wheel hub (with out hearing it myself or further diagnostics). Best thing to do is get the front end in the air and with the wheels on, wiggle them left/right and then top/bottom. If you get play in all directions, it's more then likely a wheel hub.

While wiggling the wheel, try inspecting the tie rod and ball joint. See if they appear to have "play" in them.

100,000 miles is a lot on a suspension, so some things do start to wear (granted, I got over 200,000 miles on a factory front wheel bearing on my '94 Grand Am).

Also, I have heard where some brakes that are just starting to where out (hitting the warning tabs) will emit a squeal when turning in one direction or the other.

Hope that helps a little bit.