Recently did the leaky butt fix to my c5 and the whirring or noise that alerted me to the leak is still there after 300+ miles of going easy on the differential, I did 10 figure 8s after replacing the seal. My problem is that I still hear the noise when decelerating at any speed above 40mph. I've been under the car checking on it after every drive and it's no longer leaking but I still hear the noise, I replaced the fluid with Mobil 1 75w90 gear oil and added the additive. I made sure I added the correct amount and it has been driving me absolutely nuts because I was hoping that if would be fixed. Does anyone have anything else I can check or do to resolve this annoying sound?

 

Anyone have any ideas? I know threads have been created already but I have not seen any with this problem this far.

 

When I had mine fixed I used Royal Purple lube and GM additive and no issues, Is it possible you ran it low and did some damage to the unit?

 

From the time I heard the noise to the time I replaced the seal and refilled the diff was no more than 20 miles, I have a feeling the noise might be a bad wheel bearing now but I'm not sure. I would think that it being low enough to hear and driving for 20 miles wouldn't hurt it but I hope it didn't. Anyone have this problem?

 

Does anyone have insight on the rear wheel bearings and how to just replace the bearing and not the whole hub? That is if it is even possible just to replace the bearing and not the whole hub. And if there is anything else this whirring noise might be?

 

Check your wheel bearings by grabbing the top and bottom of the tire. Push the top in and pull the bottom out and vise versa. If you feel any play then the wheel bearing should be replaced. You should not be able to move the wheel at all.

If your hubs are good, I would drive it for about 1,000 miles (it can take that long for noises to change / go away). If no change in noise, then you probably need new gears and/or carrier bearings. the noise isn't going to hurt anything, it's just an annoyance.

 

Many times it is just one bearing. So when you did the figure 8's did it make more noise going one way than the other. That puts more weight on one side thus more noise and bingo that is the weak one. Just an old school idea that has worked for me with success.

 

Thanks for the replies it's good that at this point it's only an annoyance and no harm should come up first thing tomorrow I'm gonna jack up the rear and see if one of the wheel bearings is bad, and if not I guess I learn to enjoy the terrible sound, once again thanks for the replies guys.

 

Not sure how many miles you have on it or if your running older run flat tires but sometimes the tire noise can be confused with other problems. May not be in your situation but just wanted to mention it. Good luck in getting it resolved.

 

The hub and bearing are one unit so there's no way to just replace the bearing. For a street car, the Timken or standard SKF replacements are decent. You should be able to get one or the other at most decent parts stores.