what holds the front wheel bearing / hub in place?

[flapjack]

My brakes felt and sounded like the pads were spent. Sounded like metal on metal. Looking at the disk, I see a few stripes on it, looks like the outside pad is worn.  After taking the caliper off, the pad has a good 1/8" of life left in it.  The disk was rubbing against the caliper carrier. The part that doesn't move!
The big nut on the end of the axle was loose.  I'm thinking, this gave it the freedom to move around, but when the wheel is tightened with the four lugs against the hub, does it matter if the axle nut is loose? Does that big nut hold the hub in place?

[truckinwagen]

the wheel bearing has a two piece inner race, if the big nut is loose and the car is driven the inner races are allowed to come apart, destroying the bearing.

unfortunately your wheel bearing sounds like it is bad.

[flapjack]

Great! it's only a year old too . ..   
thanks for the quick reply

[truckinwagen]

I had the same thing happen to me a couple years ago, it is vitally important that the axle nut stay incredibly tight.

[rabbitman]

My Dad's golf had a "loose bearing", turns out the nut was loose so I tightened it and that fixed everything. I don't think the bearing got wrecked either since it's been a few months with no issues.

[truckinwagen]

might have gotten lucky, it doesn't take too many miles with a loose nut to wreck a wheel bearing.

[lord_verminaard]

Also remember that the axle nuts are supposed to be one-time use only.

Brendan