Rubbing noise while driving, gets louder when braking

[joesaiditstrue]

Started to hear a rubbing metal on metal sound which gets louder while braking. Replaced wheel bearing, and have new pads and rotors installed

Mechanic said it's my front differential, I just had a repurposed one installed 6 months ago

Could it be anything else and this is just a misdiagnosis?

 

[christo829]

How many miles on the vehicle? You might want to check the fluid in that repurposed front
diff. I'd expect a failing front diff to growl or whine more than rub. Any chance one of your
dust shields is bent or has crap stuck behind it? Or is it a harder sound than that?

Did you do the brake and hub work? All four wheels? How did the calipers feel when you retracted them for the new pads/rotors? If they were stiff, you might have a sticking piston or slide pin.
If it was a pad dragging, I'd expect it to go away when you apply the brakes, but a sticking caliper
might allow a pad to drag, then slightly or partially increase pad pressure, making the sound louder,
but never pushing it firmly against the rotor.

This was happening before the brake/rotor/hub replacement I'm assuming, but was it
happening before the front diff replacement?

Good Luck!

Chris

 

[joesaiditstrue]

296k miles

it was much louder before the front diff replacement, it went away completely after swapping in the other one

only did the front wheel brakes

could replacing the fluid fix this or is it one of those things where once you hear the noise, you're screwed?

also hearing a weird chirping sound when accelerating slowly from a stop on the drivers side

 

[Maverick6587]

I would expect the brakes to be making the noise, especially if it gets worse while braking. How long ago did you replace the brakes and with what brand? Do you haul anything very frequently? Does the repurposed diff have any kind of warranty on it still?

I would try checking the oil level and probably just change the oil to be safe. I know when the TC starts making noise it is recoverable with a fluid change. Maybe the front diff is as well?

Could you record a video of the noise for us? It would be easier to diagnose being able to hear the noise.

 

[Mooseman]

What about the dust shields? They're the usual suspect of these noises. Can change when turning or applying the brakes.

You could drain the fluid and check for metal. Jacking up the front and turning the wheels while listening might help pinpoint the noise.

If I was getting the same noise after replacing the diff, I'd be looking elsewhere. Two diffs making the same noise is possible but not probable. I'd think something was disturbed during the diff replacement that made the noise stop for a while and then came back. That's why something like brakes or dust shields are more probable. There's also the wheel hubs.

 

[Sparky]

Double check your brake work. Check those slide pins for smooth easy operation, look for any funny wear/rub marks on rotor and pad surfaces, etc.

 

[joesaiditstrue]

So an update, I ran my hands around the rear rotors and the passenger side is VERY rough, drivers side seems fine, the rubbing noise seems to ge coming from the rear

so I guess the repetitive rubbing I'm hearing from the front while driving is likely the differential, the rubbing grinding in the rear seems to be the brakes

So should I check the front diff fluid and if its low, could replacing the fluid salvage this?

so tl:dr

metal on metal grinding in rear seems to be brakes
rubbing while driving and chirping noise in the front end likely differential unless someone here thinks it could be something else

 

[Sparky]

You positive the chirping noise is from the front?

Check/change rear brakes/hardware as necessary. Check front diff fluid level, and check the front driveshaft U joints. Check the flimsy metal shims/guides the pads ride on to make sure they aren't lightly touching the rotor edge.

 

[joesaiditstrue]

chirping is from the front driver side it seems

Man this is all happening to me at like the worst possible time

ordered new pads and rotors from amazon but they wont be here til after Thanksgiving, f**k my life

I need my car for my job. How long can I drive on this rear rotor if I can literally feel the scraping in the brake pedal? I can hear the scraping reverberating off of parked cars as I drive by with my windows down even when I'm not pressing the pedal down, it gets louder when I apply the brakes

4 days? 5 days?

 

[Mooseman]

I just noticed today a chirping in the back that has come back. It's just at low speed. It was really bad until I took everything apart. I think it may be coming from the parking brake.

I think such noises are more annoying than anything so I wouldn't worry rolling on it for a while more. I let mine go for months before I did something about it (and it's back )

 

[joesaiditstrue]

this is the chirping, just recorded it. seems to happen when accelerating from a stop

I need a new car lol..

 

[Mektek]

You don't need a new car - just a properly serviced Trailblazer
After going for a short drive, check the temperatures of each rotor. If you notice that some are much hotter than the others - you've found the problem wheel.
The front brake pistons can swell as they age, which will cause the problem of sticking pistons when you install new pads. Stuck pistons can cause a scraping sound as you drive.
Also, jack up each wheel and check how much drag there is - if it's hard to turn that also indicates stuck pistons. You can replace the pistons or just get rebuilt calipers.

 

[christo829]

That almost sounds like the wear tab just starting to hit the rotor.

When my fronts wore down on the passenger's side, I never heard the wear tab
hit, and the grinding of the pad sounded like it was coming from the rear. When
I tore in to them, I was surprised to find the front passenger's inboard pad had gone
down to metal. Luckily, I had ordered a full set of rotors and pads front and rear. The rears had only just started to squeak.

I never did figure out why that one pad had ground down. The caliper pistons weren't stuck, and
the slide bolts moved easily. I've checked them a few times after changing, and wear seems normal
so far.

Oh...and I drove it on that crapped out pad/rotor for at least a month. I wouldn't recommend that,
but you can probably get away with it until your parts come in. Just be extremely aware of your stopping distance.

Good Luck-

Chris

 

[Brian K]

I had a chirping noise I was positive was coming from the rear passenger wheel. Took it all apart and cleaned everything and I still heard the chirping. Turns out it was the driveshaft U-joints. Had them replaced and all is quiet again. The noise was worse backing up for some reason. 150K.

 

[paul2005tb]

Check the brake shields carefully.