I searched around the board before, but most of the threads related to this talk about ticking noises. I feel like I've skipped that step; although about a month ago I would randomly here what I guess could be described as a very slight ticking noise occasionally from the front end. I was mentally prepping myself for the eventuality of replacing the CV joint/axle, but figured it was something I had a little bit of time for (i.e. something warmer than the 8 degrees today). About a week ago, I had the trifecta of ABS/Tire pressure/ASC light go off. It was the day we had a pretty significant (~45 degree) temperature drop, so I checked the tire pressure and sure enough, had a couple times a solid 10 pounds low. Filled them up, lights went out for half a day, then came back on. Checked tire pressure, everything was good. According to internet diagnoses, likely candidate is wheel speed sensor(s).

Well today while returning from a meeting 2 hours from home, while cruising down the highway at about 80, I heard something much louder and constant. Thankfully I was coming up to my exit so I pulled off the ramp just to make sure this wasn't some figment of my imagination like road noise or something (wishful thinking on my part). Checked tire pressure just to make sure nothing there, everything good. I pull back out and sure enough it sounds like someone trying to grind marbles coming from the front end. When this all went down I was about 12 miles from home and with the extremely cold temps, I decided to push it and make my way home (at 45 mph instead of 80) instead of sitting on side of road freezing to death. Things I noticed. It went from barely anything when I pulled off the ramp to really bad as I pulled back onto the road. Once it reached that point, it didn't appear to get any worse. Car out of gear and coasting had no affect on level or frequency of noise. Turning, braking, accelerating, also had no affect on noises, although obviously there was a correlation to speed. Sitting still at idle, no noises or vibrations. I only add that as one of the many things I was running through my head is that maybe my transmission was coming apart, but I feel confident that's not the case. Something I would have expected was to feel more vibrations, either in the car in general or in the steering wheel. I noticed no abnormal vibrations at any time, no pull on the steering, just the grinding marbles into smaller marbles sound. Made it home, parked it. It's still wicked cold out, but it's going to warm up next week. Thinking of ordering at least the drivers side CV axle assembly (my ears seems to tell me this is on the drivers side). Anything else this might be? Any pros or cons to just replace both while I'm doing this, I'm leaning that way. If I order the complete CV joint/axle assembly, is there anything else I need to replace at the same time? Like some other joint/seal that should be replaced at the same time? Sorry for the long, post, but figured I'd include all of the information. Thanks in advance.

 

Jack the car up and see if the wheel wobbles that would be signs that the bearing is involved.

 

+1. Also roll the wheel forward and back. If you hear the axle click when you switch direction, you know what you need to replace.