Weird Noise from rear of vehicle
 

Hey guys. I have a noise coming from the rear of the vehicle. I can hear the noise at low speeds very well. I can hear the noise by pushing the car on a flat surface with car turned off. I can hear the noise while accelerating, decelerating, etc. The noise sounds like there is a metallic cylindrical object, rolling back and forth in a tub of metal...like the spare tire area. It is that hollow metallic sound that a heavy piece of metal like a socket would cause rolling in the spare tire area. The noise gets "faster" as speed increases, and slower as speed decreases. It is not a whine or a squeak. If I push on the shocks and bounce the car up and down I do not hear anything at all. Does anyone have a clue what the hell this could be? I've never heard the noise before. Car drives fine and brakes fine. Perhaps a rock? CV joint, wheel bearing?

Part 2. I jacked the car up. Rotated wheels and could not make the sound. Tires had no debris in them. Shook wheels and there was no apparent play in the bearings...both wheels felt the same. CV boots are in place with no stuff leaking out. Took it for a drive...first couple minutes I heard nothing...then it started again (and did not stop until I parked the car) It seems that the noise is loudest the moment I let off the gas, and also it is pronounced when I first engage the gas. The noise is present while driving and decelerating, but more pronounced on the above 2 cases. Driveshaft is not leaking at transmission tail housing. I can turn the driveshaft an inch or two before the wheels start moving. I can also rotate the wheels while holding the driveshaft and keep the driveshaft in place. My wife "THINKS" it is more prominent on the right side of rear. I took the car in circles both right and left and I could still hear the noise. Car has sat for a month or so. Only mods to the car since it has been sitting was door bars (not likely related) and Rear CAnon Brace from FM. The noise is very rhythmic. This leads me to believe Ujoint on driveshaft. Also since it is most pronounced getting on and letting off throttle, this would seem to sound like ujoint as well as that would be when the slack is taken up/let out of a worn u joint. Anyone?

I have (always had) an array of weird sounds from the rear I can't diagnose, and others I can. :vash: I mean on the car. :rofl:
Its not a whine or a squeak but is it possibly a clunk?

What about...
exhaust touching stuff,
brakes clamping constantly, park brake looseness or tightness,
shock bolts tight,
have you got all the brake retaining clips,

The noises you mention made me think hubs at first too. Even if you didn't have any free play it could be the hubs... how many kms on your car?

Its not the exhaust. I can make the noise by pushing the car so I should be able to make the noise by turning the wheel, but I can't, so to me it isn't the brakes. And the fact that the noise occurs with brakes applied or not applied, leads me to believe its not the brakes. 135k miles on the car. I just messed with the ujoints on the driveshaft. Car is jacked up in rear. Rear of driveshaft I can not feel any play. Front of driveshaft I can put the whole thing up and down about a mm. I can see the part that goes into the tailshaft move. I don't know if this is a sign of a worn ujoint or not, or if its normal. There is a clunk like noise when I let off gas/get on gas. I can hear the noises best in 2nd gear. After the clunk, it is the rhythmic sound. Maybe bed spring sound is a better description than what I described earlier. Also, the noise is not like something only I can hear. It is enough for my wife to be like "please take us home and don't drive it anymore" and my wife knows zero about vehicles.

Could it be the rear diff?
sounds a lot like mine when it finally split.
what year is your car?

2002. Torsen. I put the car on jackstands. Car running, I hear no noise in forward or reverse. The diff is silent, no whine (it never has had a whine). I checked the cloverleaf weight on the diff and it is in the proper position and has not failed. I'm doubting its the rear diff.

I scrolled through the thread and dont see any videos...

I"ll try to capture some audio today.

I took the car and drove near a curb. I got my wife to listen. I could make the noise going extremely slow so I made the car go forward a few yards and backwards. Wife was confident that it was the passenger rear. She said it sounded like something was in the wheel. I had already checked the wheel for debris in the brakes, so I checked the one thing that never crossed my mind...lug nuts. I have the aluminum 949 lug nuts. I torqued them to spec when I installed them (cheap torque wrench) On the rear pass side, I was able to remove 1 lug nut by hand. I tightened the lugs and went for a drive and the noise is gone. Evidently the one lug being loose, since we only have 4, created enough imbalance to make the noise. It had no perceptible vibration though. I got a good Craftsman Tq wrench and checked all the lugs. All the lugs on both rears were loose to some kind of degree...only one was super loose though. The fronts were still in spec at 75 ft/lbs. I did capture an audio recording though. In it in the background, you will hear the noises I described earlier.

Just to clarify... all your noise problems were solved by tightening your wheel nuts? Or is the noise in the video something different?

All of the noise in the video was cured by tightening the wheel lugs. Freak problem but thankful for easy solution.