I was on a road trip this weekend and its the first time I actually sat in the back of my own evo and I noticed a really like whining from the rear. It starts to be audible at around 40mph and gets progressively louder up until about 80 or 85mph.

The only was i can describe it is like a howling that sounds like its oscillating...kind of like when you tune a guitar right before its in tune you get that duel vibration sound.

I looked up videos of the tcase whine but mine isnt nearly as loud as that as i can really hear it from the front seat but its deafening in the rear. I did get into an fender bender this winter when i ran the front ds wheel up on a curb but when i checked the wheel bearing by shaking the wheel it wasnt loose. Would a bad wheel bearing in the front cause such a loud noise in the rear? Is there any other was to determine if its a wheel bearing or the TC?

I changed my tc fluid a few weeks ago and there was no metal shavings in the oil so i really dont think/i hope its not that.

Can anyone chime in on their experience with wheel bearings? My car has about 78k miles on it and the bearings havent been replaced. Whats the milage you should start looking at replacing them? I dont want to replace all of them because its going to cost about 500$ in parts but id like to find a way to tell which one it could be.
thanks for the help all!

 

Just because you hear it in the rear doesn't necessarily mean it's coming from there.

Are you the original owner? Aftermarket clutch? Have you changed any bushings or mounts? All these can change the acoustical dampening that was originally designed with the car.

Does the whine significantly subside after 80-85mph? I have a similar whine, but it's just the normal gear whine. It's seems the harmonic frequency for something is my driveline is around 80 mph.

 

Im not the original owner. I bought the car with 15k on it so i put most of the miles on it. I just got a act hdss clutch installed and i got all of my fluids changed at the same time.
Ive noticed the sound before the clutch install but im not really sure when it started to be honest. My car is pretty loud with the exhaust but now that i really listen, like if i take it out of gear on the turnpike, i can hear that harmonic sound pretty well. Im not sure if i hear it doing 90 or above ill have to test that out when it stops raining here.

The only mount i changed was the transmission mount to a stiffer one to help with shifting and i have a rear sway bar installed along with MR shocks with swift springs.

I was thinking it could just be normal and im just paying attention to it now but if its not and its a wheel bearing or tc id like to get the problem solved before its a bigger issue.

 

I have had a bad wheel bearing issue in the front of my car. Turning while driving from side to side made the sound disappear and that is how I diagnosed the problem. Post up a video if you want some more insight.

 

Yea i need to try the side to side turning but it happens at higher speeds so its not like i can take any real sharp turns to see if it goes away. I Will try to get a video of it in the next few days but thanks for the help. When you had a wheel bearing go in the front could you hear it more in the rear of the car?

 

I highly doubt that it's a wheel bearing. A bad bearing tends to sound like a low roar/grinding and get's louder as the speed increases.

The whine is most likely driveline noise. I noticed mine when I replaced the front cross member and rear diff support bar. The noise actually got louder after I installed the shep tc with the quaife lsd.

 

No, when mine went bad it was pronounced towards the front of the car. The side to side trick doesn't have to be crazy turns, just slight from one side of the lane to the other. Be careful.

I agree with Mith though, my bearing noise increased with RPMs until it hit its max around 4500 or so. When is the last time you did a fluid swap in the rear diff and t-case? Check the fluids to see if anything looks out of wack then go from there...

 

The fluids were done about a month ago and the shop didnt see anythign out of the norm. And the sound does increase as my speed increases. You can hear it at around 40 mph and its the loudest at about 70ish then the engine noise tends to drone it out. Maybe ill check the rear diff fluid again just for the hell of it though. Thanks guys

 

its your transfer case..

 

I could be your differential bearing(s)... I owned a car once with symptoms similar to yours and that's what it was.

 

Granting I know it's not safe can I put my car on 4 jacks and put it in gear and listen for the noise outside or would that not work with the awd

 

sounds like your tcase is shot. what kind of oil did you put in it after doing the clutch and how much.

 

could be tires.....as tires wear down they can get loud try putting it on a lift and see if you hear anything

 

Its OEM fluids put in... I do have ****ty tires on right now and it could be that. I have some for of cooper tires on the stock rims right now. I plan to get it up on a lift and see if i can hear anything.

On another note another weird thing i notice that could be related..When i accelerate really hard i here the oscillating noise louder and when i go to brake it feels like my rotors are warped but after the first time i hit the brakes they dont vibrate again. Could that be a sign of a wheel bearing?

 

wheel bearing is pretty obvious, like you checked before, just getting the tire up and shaking it..... and oscillation if not wheel bearing could just be a badly worn tire or such

a whine by itself would just be a vibration hitting the right frequency, but with an oscillation i'd think something isn't rotating correctly, like something not tightened(lug nuts) or not balanced correctly

check your wheel weights, could be one just fell off