Rear end high pitch humming, Wheel bearing, diff, tranny?

SON240sx Automotive
1

I have this very loud humming, ringing, noise which is coming from the rear end I’m having difficulty diagnosing. It has gotten so bad I worn ear plugs today. There is no vibration with this noise. Car still feels as good as it did before the noise started. Its been getting progressively worse. It needs attention asap.

The noise starts at about 50km and gets louder until 100 then starts to go away at 120.

It is louder under accerleration. It also is louder under breaking, not as loud. Does not seem to be affected by turning.

Things I’ve done so far. Jacked car and looked for play in the wheel. Nothing
Checked exhaust for leaks or touching something. Nothing. I’ve also turned the car off while costing from 120km and the nosie is still present.
I also have a new 1pc drive shaft so its not the hanger bearing

The noise is there in any gear or netrual. Clutch in or clutch out.

I have ordered new wheel bearings to install this weekend but I’m worried its not the cause and it maybe the diff or a bearing in the trans. How would I be able to determine? Any suggestions would be great.

2

best way of knowing if its the tranny or the diff is to change the fluid (which should be done failry regulary anyways…) and check the old fluid for metal. metal shavings is always a good indication of wear. But by the sounds of it i would say it’s probably a wheel bearing. Jack the back end up and get a freind to start it up and put it in gear, should easily be able to determine what side if thats the cause.

3

Thats for the response. I changed both fluids back in june. Some shavings in the diff but nothing I would be concerned about. Its doesn’t sound at all like too much backlash or a missing tooth. I was more concerned about bearings in the diff or trans. I’m glade you think it’s wheel bearings though, I was just concerned that turning wasn’t making much a difference in noise. Could be both I guess.

4

Well new wheel bearings in and the noise is still there. Maybe the output bearing on the transmission, are they worth replacing?

---------- Post added at 06:05 PM ---------- Previous post was at 05:35 PM ----------

f that idea. I can’t find a thing about doing it. I’ll just drive it and turn the music up

5

mine does the exact same. pretty sure its just an old diff or hanger bearing. i dont even notice the noise anymore really haha.

6

If you have solid aluminum subframe bushings then welcome to the club. You’re simply hearing the diff do its thing now that the rubber is gone.

7

I’ve had subframe collars for a couple years. I’m getting it on a lift tonight so i can hopefully pin point the source. I was thinking tyres but the noise doesn’t change with road surface so thats why I’m back to thinking diff.

8

I got the car in the air today. Its 100% the diff. It just screams at about 80km. Must be a shot bearing.