Humming noise driving me nuts!

[drh_5.0]

Alright sooo....I recently just fixed a vibration that I found out to be a bad factory UCA on my 2012 GT. Which ended up damaging my 1 pc driveshaft's yoke I had on there...

But before I did that I had gotten new wheels and tires from American Muscle and upgraded to a set of brembos in the front and upgraded brake lines all around. After doing so and going for a drive I heard a loud humming noise that gets louder as I drive faster. I tried to see if it goes away with clutch in...hard to tell but it does seem more faint... dk if it's because the car feels to slow down faster than usual too.

I have less than 35k miles on it but I have upgraded a lot on the car and is now supercharged so more wear and tear is expected.

My question is what is making the humming noise? Since it only started when I upgraded wheels, tires, brakes...and did NOT go away when I but on new UCA and DSS driveshaft...

Leaning towards:
-Wheel bearings (which with low miles idk?)
-Axle Bearing (know nothing about them)
-New Brakes hanging up somehow
-New wheels or tires bad (don't think so, seem perfect shape, and they are Forgestars who make good stuff)

Anything else I could be missing? Could there been something else damaged from the bad UCA in the drivetrain? All input is much appreciated!

 

[MKMotorsport]

Seemingly that is a lot variables... couple more to consider would be pinon bearing, and carrier bearings.

 

[SquishyDaFishy]

start lookin at what you did just before the humming noise started. i am leaning toward trans input shaft since you damaged the yoke.

 

[drh_5.0]

I had to have the shop reinstall the factory pinion flange to since the other driveshaft replaced it and the new DSS one reused the factory. They didn't mention any issues with the pinion bearing but that doesn't mean isn't something wrong with it. Will have to take a look and see!

 

[drh_5.0]

start lookin at what you did just before the humming noise started. i am leaning toward trans input shaft since you damaged the yoke.

Only thing that was done before humming was wheels/tires and new brakes all around...I'd like to rule out wheels and tires since I feel no vibration. Brakes? My fear is damage of more in the drivetrain.. input shaft would suck! How would I check that? Is it internal or is it just the joint where it meets the driveshaft? I actually did a full tranny flush and changed to Royal Purple Syncromax...had a filter on the old fluid and happy to see there was no metal chips of any kind. Don't know if that makes difference...but I know these MT82 trans are know as a weak point of the new 5.0s

 

[gt5.0coyote]

I had the same issues as this. Humming noise. Did you take the little washers out of the outside of the rotor? Called AM and talked to one of the bosses and he told me to do this. I didn't do this at first and the wheel wasn't spinning round and it had a wobble in it. I also changed my wheel bearings and this may have also solved the humming problem. The wheel bearing may have been bad for a long time and the stock tires road noise may have covered it up.

http://i212.photobucket.com/albums/cc5/mattdocs40/BrakeJob/brakejob2.jpg

 

[drh_5.0]

I had the same issues as this. Humming noise. Did you take the little washers out of the outside of the rotor? Called AM and talked to one of the bosses and he told me to do this. I didn't do this at first and the wheel wasn't spinning round and it had a wobble in it. I also changed my wheel bearings and this may have also solved the humming problem. The wheel bearing may have been bad for a long time and the stock tires road noise may have covered it up.

http://i212.photobucket.com/albums/cc5/mattdocs40/BrakeJob/brakejob2.jpg

Thanks for your input. Yeah I actually removed that dumb washer on each rotor on my last set of wheels. What year was/is your car that had the noise? And how many miles were on it at the time of wheel bearing change? Did you go with factory bearings or aftermarket? Just trying to see if it could really be possible that my bearings are shot at 35k miles...but with the added power I guess anything is possible. :shrug:

 

[drh_5.0]

**UPDATE**

So I have tried to eliminate the noise via the clutch or brakes (including using ebrake)...Still there at higher speeds but seems to go away with lower speeds? comes and goes...MUCH more noticeable 1st-4th 5th and 6th it does it too but not as intense.

After driving into work this morning and parking I felt the rear rotors, warm...but not too hot to touch so guessing rear calipers are fine...but I should check on those too.

*I replaced the rear wheels with my old ones and try to eliminate the tires being the issue. Sound still there.

*Checked the rear wheel bearings for play by pulling on the wheels when jacked up....nothing budged.

*Heard clunking when just tapping the gas? Also heard a sort of grinding when I took sharp turns?

 

[five.slow]

I had this issue and it ended up being my brand new front tires.


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[califsp]

Really sounds like drive shaft/transmission. Put the original drive shaft back on?

 

[Carbd86GT]

Really sounds like drive shaft/transmission. Put the original drive shaft back on?

I would just rotate the shaft 180 degrees and take it for a spin. That does the trick quite often.

 

[gt5.0coyote]

Thanks for your input. Yeah I actually removed that dumb washer on each rotor on my last set of wheels. What year was/is your car that had the noise? And how many miles were on it at the time of wheel bearing change? Did you go with factory bearings or aftermarket? Just trying to see if it could really be possible that my bearings are shot at 35k miles...but with the added power I guess anything is possible. :shrug:

Sorry for the late reply man. The car is a 12 gt with about 18,000 miles on the frpp gt500 rear end. Stock replacements.

 

[drh_5.0]

It made the noise with the bad 1 pc driveshaft and still with the new 1 pc driveshaft on. For that reason I'm ruling out driveshaft for now.

I would like to swap out front wheels to old ones but they won't clear the brembos I got on there now...maybe my OEM ones will and can try that too...I would think fronts would give me a bad vibration in the wheel though? Did you experience any steering wheel vibrations five.slow?

**UPDATE...part 2!**

Put the new wheels back on the rear and I notice even with ebrake off the my rear bads are basically touching rotors..but the wheels spin pretty easy freehand. If i just rotate wheels back and forth I hear a knocking which is coming from the drivetrain...I think it's like by the pinion flange..dk didn't have it raised enough to get better idea.

After all that I took car out for quick 12 min drive, noise I'm still there like I figured...Didn't drive it hard or brake hard but when I got home I felt all rotors...rears are vented and were much hotter than fronts which are not vented. Is that normal? I wouldn't think so...

My thoughts now are brakes are rear differential problems.

I plan on bringing it to one my local shops I go to on Monday see if they can help find it at this point. Go for ride to hear noise then get it on a lift and gently run it see if it makes same noise. Hopefully get some answers and will report for others looking for similar answers.

 

[drh_5.0]

Brought it to shop today and after putting it on the lift and took differential cover off...

Found there is a decent amount of backlash/play on the pinion...upon further inspection 1 small chip on differential gear and 1 small chip on pinion gear. Also there is a few groves on the differential/posi itself..just one which is weird but think that is from the worn out yoke on old 1 pc driveshaft.

Not positive if that is noise I'm hearing but looks like I will need to replace the entire gears...and probably a whole new differential/posi for the added power.

Has anybody experienced the symtpons of a small chip in tooth of rear end gears? If so what were they?

 

[M91196]

Brought it to shop today and after putting it on the lift and took differential cover off...

Found there is a decent amount of backlash/play on the pinion...upon further inspection 1 small chip on differential gear and 1 small chip on pinion gear. Also there is a few groves on the differential/posi itself..just one which is weird but think that is from the worn out yoke on old 1 pc driveshaft.

Not positive if that is noise I'm hearing but looks like I will need to replace the entire gears...and probably a whole new differential/posi for the added power.

Has anybody experienced the symtpons of a small chip in tooth of rear end gears? If so what were they?

When you say differential gear you don't mean the ring gear ? It a side gear inside the traction lock housing that's damaged and the pinion gear? Sure sound like something is come apart in there.

Fractured ring and pinion teeth are usually from shock, you can google images of failed parts. Anything broken in the tooth pattern will be noisy in my experience.

And there is probably more damage the deeper you go.
YMMV

 

[drh_5.0]

When you say differential gear you don't mean the ring gear ? It a side gear inside the traction lock housing that's damaged and the pinion gear? Sure sound like something is come apart in there.

Fractured ring and pinion teeth are usually from shock, you can google images of failed parts. Anything broken in the tooth pattern will be noisy in my experience.

And there is probably more damage the deeper you go.
YMMV

Sorry yeah I meant ring gear has tiny chip out of a tooth and pinion gear gear does as well. There is quite the amount of backlash too. Can watch a good amount of play when turning the wheels back and forth.

I been trying to find out what kind of new carrier/differential/posi whatever you want to call it to get. Was stuck between FRPP Traction Lok w/ Carbon Discs that is out of the SVT Cobras and Shelbys...or Eaton Detroit TrueTrac. Putting out about 600rwhp

Seeing as the car is mostly street driven and only on the weekend...And currently not on slicks I went with less expensive option: FRPP...Also just ordered new FRPP 3.73
and install kit. Lastly FRPP different cover with the girdle. All from American Muscle. This hopefully will fix my noise and bring back what feels like lost power. Will report back if not and will try to update if problem is gone.

Thanks for input everyone.