Hey guys, Ive been noticing a howling or roaring sound from the rear lately. I noticed this while I was turbo charged and decided to change the tranny and diff fluid to see if it helps or if I can find some metal pieces that can show me signs that something is wrong. Changed the fluids and everything looks good, no metal, but noise is still there. Decided to let the noise be since it was not crazy loud, it was something you had to sit and listen for. I recently put the car back to stock and I can really hear the noise more now. My previous exhaust used to mask out alot of the sound.

The noise seems to be the worse at around 40mph. If im going slower or faster than this the noise is still there but not as bad as being in the 40 mph range. If I put the car in neutral and let it roll the noise seems to go away, but still to me the rear end seems a little louder than it should be.

Ive tried searching the threads for a similar issue, but nothing seems to sound like my situation. I dont have any kind of whinning sound, no vibrations, and shifts fine. The only things that I could think of is something wrong with the rear brakes, or maybe wheel bearing or hub damage. I am not sure.

The car is all stock except some Espelir lowering springs. What you guys think? Hopefully Billman can chime in on this one.

 

Wheel bearing.

Jack up the dif, spin each rear wheel fast by hand. One of them you'll hear roaring.

 

Thanks for the fast reply Billman,

I just tried this, jacked up the car by the diff and tried spinning each wheel by hand as fast as I can . I dont seem to hear roaring, i hear slight hissing (like if the brakes are slightly rubbing the rotor). I did notice something else though. When I rock the wheel back and forth there is a slight bang in the change of direction. When I look at the axle i see there is some play. it moves slightly on its own before it get the driveshaft to spin with him. Not sure if this is normal.

I think I would hear this more if I was able to spin the wheel in gear. Because when Im driving the car I hear the noise mostly when im in gear cruising. When i take it out of gear and let it roll in neutral the howling nearly goes away. If I go slower than 40 mph, or accelerating past it the noise also seem to go away, but in my opinion in every situation the rear end does seem a little louder than its supposed to be.

 

Bump.

 

my experience is a howling- a howling that pervades thru the structure and seems to be piercing my brain at a given speed- is, as billman said, a wheel bearing. What helps me determine if its a wheel bearing for sure, is if my wife says- "man is your car loud on that side." or "I can't hear myself." or "what is wrong with your car?"

She'd love to go to Miami, so if you fly her down, she'll be able to help you out too.

Seriously, i also find if i very slightly drift from one side of a lane to another at the howling speed, then the pitch will change ever so slightly. I reason this happens because the bearing has more play in it hence changing the pitch of the noise. Wait till you press the bearing out and see how pitted the ball bearings are- its pretty incredible to see.

good luck!

​​​​​​​darcy

 

lol this was a great reply. Thank you. What gets me though, is that the sound seems to go away when rolling in neutral. If it were wheel bearings wouldn't it make the sound in neutral and in gear?

 

Hoping billman can get back to this thread

 

It wouldn't make noise in neutral because the axleshafts are not loading the hub/wheel bearing. Also if you only hear the noise turning one way but not the other it's a wheel bearing. PS I'm in Miami, if you need any help getting that fixed let me know.

 

What kind of tyres do you have? Any cupping?

 

I was going to suggest trying different wheels/tires but he said the noise goes away in neutral