Rear diff rebuild due--254000 miles

So I've owned my 2000 Tacoma since 2003. I got it with 30k on it and now have 212K. Over the last 6 months my truck has been making a light screeching metal sound when driving, mainly at freeway speeds, but now I'm hearing it on city streets. I know what bad bearings sound like and this doesn't sound like bearings. I'm wondering if that sound could be the bearings. It kind of sounds like the wear indicator on the brake pads but those are fairly new. Have any of you guys heard anything like that before? Thanks in advance!

 

Prolly best to pull the wheels and at least look at the brakes. Typically you hear the brake pad squealers at low speeds

 

Yeah I first noticed it at freeway speeds. I will look at the pads again though. The rotors and pads are about a year old though.

 

Also check the dust plate on your brakes. That thin sheet metal might be contacting the rotor.

Can you tell at all where it's coming from?

 

That’s a good idea, it sounds like the front, but the sound isn’t consistent like that. I’ve been in the collision industry for 20 years and I’m aware of weird sounds that car and truck make. I will check that though.

 

your avatar looks the same size as everyone else's...

 

Has the sound worsened over these 6 months? Or pretty much is same and just comes and goes?

 

It sounds the same is it always has, seems like I hear it more at freeway speeds though. Bearings are more of a vibration and humming sound right? I didn't know if they sounded different on these Tacomas though. I will look at the brakes and the dust shield though.

 

Yeah, how you describe the bearings is how I'd describe it as well

 

Sometimes threads just end with no resolution.
Or maybe the OP is still living with the noise?

I came across this thread while searching for possible causes of a noise coming from my driver's side front wheel.
Kind of a wisp wisp wisp sound, with tempo directly proportional to speed.
Didn't really sound like a bearing or worn out brake pad to me (which I've heard before).
Not a squeal or screech, or hum or rumble, just a muted wispy sound, only vaguely metallic sounding.
And here's the thing:
First thing in the morning it would be there, loud enough to hear while driving at highway speed with the window down.
Later in the day, start up and drive, and...no noise.

I'm driving only local lately, and was gonna wait until I gotta get my state inspection done next month.
But my wife wants to visit some relatives this weekend.

Okay, started doing a little research, and, among others, found this thread.
And the following post:

Yeah, okay, I guess it's time to get under the truck and actually look.

Well, the dust shields (or whatever they're called) are pretty rusty.
The one on the driver's side was rusty enough to be buckled and ragged on the bottom.
I reach up and pieces come off.

Anyway, that was the cause of the noise alright. A rusty shield intermittently contacting the rotor.
I bent the shield away from the rotor. Noise gone.

Question:
Should I bother replacing those shields?

 

If they're rusty and breaking apart or bending themselves into your rotors then yeah you should replace them. Otherwise I wouldn't worry about it.

I bent mine back when I was doing my tie rods last week and forgot to bend them back into place, driving to work the next day was interesting to say the least. Thought my wheel bearings were taking a dump it was grinding so bad lol

 

Yeah, I will have them replaced.
I'm just curious how important it is and what might happen if the rotors are partially exposed.

Thanks for the reply.

 

It's a dust shield, all it does is keeps or tries to keep brake dust off your wheels.

 

Update on an old thread. Rear end needs to be gone through and rebuilt. Almost 255k on it. Fluid is clean. Not too bummed out, Im redoing everything under the truck anyways, it'll give me a piece of mind knowing the rear diff is good to go.

 

OP- did you pin down the noise? Dust shields? This sounds odd, but have you checked your front differential fluid as well- esp if you have a.d.d/CVs… I had a pinion seal leak and unfortunately found out by hearing my front diff grinding.

 

Sounds like its the Carrier bearing. The sound was definitely coming form the rear of the truck while driving. I had the truck at my friends shop yesterday and we isolated the noise to the rear diff. He has a gear specialist he uses and he is going over there soon to verify it, but 98% sure thats the issue. We went through the entire truck, not just for that noise, but for restoration purposes. My Tacoma has been parked and rarely driven for 3 years. Im bringing it back to where it needs to be, plus some. Front diff passed with flying colors.

 

@Clearwater Bill, your talking about the Center Bearing that supports the driveshaft. The Carrier Bearing is related to the rear diff. I think those are often confused with one another.

 

Realized immediately after I posted, which was why I deleted the post. You're too quick.