Rear End (Diff??) Noise

[N3philum]

So.. without too many details i destroyed a wheel, bent the rear subframe and destoyed the control arm on the rear right side of my car a couple months back.

Everything was replaced and runs great except i have a noise in the rear diff area. The noise gets louder with increased speed. 40km/h it isnt too bad but at 60+ it gets pretty noise.. Its not a clunking or ticking.. more like a whir or grind.. almost like something is unbalanced.

Anyone have any ideas? Is it my diff? Bearings? Driveshaft? 1/2 shaft? It has gotten a bit worse since the "incident" a few months ago.

[SPICcnmFD]

I'd say bearings. Did you replace the wheel bearings on both sides of the car if not I'd start with that.

[N3philum]

no. i didnt replace the bearings. everytime ive heard bad bearings its usually under load (when turning). it also sounds like its coming from the diff/drive shaft area so i didnt even think about that.. how would i check it before i actually replaced em?

[josh18_2k]

if you managed to bend the subframe, i wouldnt be suprised of one or all 3 of the diff bearings underwent some kind of lateral stress. it could also be your backlash in the diff.
did you change the diff during the repair? the whining could be totally coincidental too. weirder things have happened.

[N3philum]

no, i didnt change the diff at all. i replaced the things that i visually could tell where broke. (control arm, subframe, wheel)

I was thinking it could be a warped rotor, but i havnt really had the time to look into anything. there was ZERO noise of this kind prior to me being a dumbass.

[N3philum]

i checked the wheel bearing by jacking up the back of the car and trying to shake the wheel. its solid as a rock so im not sure if thats the problem. I really have no idea whats going on. Anyone have any other (new) suggestions? I guess my only option now is to swap the diff out or change the bearings. i have a 2 way so i might as well just get a different pumpkin and swap the whole thing. i really cant afford for my car to be down for more than a week or so at a time.

[SPICcnmFD]

Did you spin the rear wheels to see if you heard a noise while you had it jacked up or just shake them??

If you have jack stands and some chalks for the front wheels, you may want to jack it up and let it run(idle) in gear to see if it makes a noise and get out and go around and listen for it.

[N3philum]

no noise at idle.. only when moving. i spun the wheels.. no noise other than a minor rub of the dust shield. its bent a little bit but at speeds i cant hear that. only that infernal grinding/whirring noise! i need a pumpkin in order to swap in my 2 way. anyone interested in JDM gears? :)

[Phoenix7]

u-joints? That's what comes to my mind when I hear whirring noise at speed. Does it make the whole car vibrate?

[N3philum]

no.. whole car is solid. just the noise.. its crazy. .car drives good as new. took it to an Autox/HPDE competition today. i got 3rd out of 12. the noise is crazy though.. its getting loud. .cars going to be down till its fixed :(

[SPICcnmFD]

So by no noise at idle you tried jacking it up putting it in gear and letting it run in 3-5 gear and see if you can hear anything??

[N3philum]

i didnt do that. i dont have jackstands at my house. or a garage for that matter. i would rather do that on a lift anyways. ill try to take care of that this weekend.

[hooper]

so you spun out and smacked a curb or what?? if so, most likely a bent axle, diff housing could have been damaged thus bearing would be taken out aswell... i highly doubt your rotor would be the cause of the harshness.. rotors tend to shake the car only on brake applications. but i would suspect the axle more than anything..

[N3philum]

replaced the diff... no change except my alignment settings are jacked. i guess the next step is to take out the 1/2 shaft and compare it to a known good. its possibly the wheel bearing as well..ill probably replace that anyway.. i hate not being able to drive my car.