It will usually make noise for a while, like even for days. The wheel can possibly wobble a little bit, and if it comes loose, it could cause the wheel to come off. Or, weld the spindle to the bearing, which then will not allow the wheel to come off.
If the bearings lock up and fail it is highly probable if you continue to drive it the wheel will fall off, and the axle stub will be trash too meaning you will have to spend even more $$$ to fix it. If the bearings are noisy STOP driving it and get the bearings replaced it is as simple as that.
Yes it can. Steve is completely wrong. I had this happen to me today. I started noticing smoke coming from the wheel bearing and then it started getting loud and it felt like something was breaking off in the wheel area. The abs light came on and I drove it around the block and then the wheel just popped off. It was crazy. Never thought I'd have something like that happen to me. I was lucky that I wasn't going fast when it happened.
Yeah, I almost succeeded in losing a wheel this way. Drove it for 2 days after it started making noise, and by the end of the second day on my way home from the parts store, it set itself up a real nice roar. Pulled in the driveway with steering going all over the place... when I jacked the car up that wheel was so loose it felt like it had no lug nuts! Took it apart only to find out the only thing holding it together was the remnants of the bearing and a flat washer that goes behind the nut! The inner bearing race had actually welded itself to the spindle, but thankfully I was able to save and repair the spindle, so all I had to replace was just the bearings and races, along with new nut and washers. Never gonna let that happen again... so lucky that thing didn't go flying off and cause me or another driver to wreck.
A bearing failure can be dangerous. If a bearing fails, there is a chance that the wheel will separate from the vehicle and/or cause a loss of steering control. I'd get them replaced and check the rest. Jack the car up on the other side and try to wiggle the tire. If it rolls around, then the bearing is bad.
