jmettee

From what I just read in these 2 threads (1 & 2), I'm pretty sure I have a bad axle bearing. The sound starts at about 5 mph & I can hear it from inside the car, but not outside. IT's a constant metallic grinding that only somewhat changes with vehicle speed. It doesn't change with braking or acceleration. It is definitely NOT a whining sound, but it doesn't resemble the typical howling/rough grinding that I am used to for wheel bearings. NOTE: this is my first experience with a rear end as all other cars are front wheel drive.

It's a 2000 T/A, LS1, auto with 88k miles.

I pulled the rear end cover & the initial find is the metal shavings on the magnet & also the piece of a gear tooth. I heard these rear gears are not the strongest, but the car drives fine so the shavings & tooth don't concern me too badly. Still wondering what comments anyone has about this.

FirstYrLS1Z

iTrader: (4)

the shaving on the magnet are typical.
based on your description of the noise,I'm guessing either axle bearing or carrier bearing.
what does that piece on your finger look like after it's wiped off ?

jmettee

It's definitely steel. I didn't see any of the gear teeth damaged or missing, but the diff was still in the car. Maybe wherever it's from has smoothed out from wear or I just can't see it. I assume someone else was in the rear be cause there are new studs on the 1 axle. Could possibly be something from when they were in there & not from the diff itself.

I got the axles & picking up bearings tomorrow (just for outer axles). I learned a lot getting in this far, so the next time should be cake. I'm going to look up carrier bearings & if they are cheap, may just swap those while I'm this far in.

Pics of the steel from the magnet are attached.

FirstYrLS1Z

iTrader: (4)

Carrier bearings require press for removal,typically a shop procedure. Axle bearings/seals are DIY but sometimes difficult.
Could be,based on look,shape,that metal piece could be piece of carrier bearing cage.
Axles bearings are 'outer' only and pressed into the rearend housing. If you're thinking that there are 'inner' axle bearings,there aren't. 'Inner'' bearings would be the carrier bearings,seen in your first pic partially visible under the right carrier bearing cap.

jmettee

Thanks. Yeah, I understand the bearing setup. After looking through the shop manual, I'll attack the wheel bearings myself. If the noise is still present after re-assembly, I'll take it to my wife's uncle's shop. I read the procedures on backlash & setting differential tension/shimming. Along with those procedures, not having the press & tools for the carrier bearing change, I'll let that part to someone who can do it quicker/easier & correctly rather than myself investing in 1-time use tools.

jmettee

I pulled the axle seals, but don't have a slide hammer to remove the bearings yet. I'm going to rent one today when I pick up my parts.

What I did see is a telltale problem with the driver side bearing (where I thought I heard the most noise coming from. The bearing feels smooth in operation, but then I noticed a metal "hair"/sliver, about 3/4" long, coming from the inside face of the bearing (toward the diff). I will know more later, but at least I have a visual on something, giving me a little more confidence that axle bearings are going to fix the issue. Will post what I find & my results later.

FirstYrLS1Z

iTrader: (4)

the axle bearings are lubricated by the rearend gear lube(a common sump situation) and anything at the axle bearings could have come from the center area carried by the recirculation of the lube.

jmettee

Well bearing still looked/felt good. The sliver of metal was from the axle housing apparently from the last time a bearing was installed.

Soooo, 2 new axle bearings & the noise is still there. But I did notice that the driver's side axle (or perhaps just the wheel flange) is bent pretty significantly. Don't know how I didn't notice this before doing the work, but I guess in hindsight I was already thinking it was a wheel bearing & probably didn't suspect a bent axle nor look for it. I know the wheel is installed correctly as I thought the flange looked oddly off-center when turning by hand during the axle installation.

So the axle is bent, but the noise is still just a constant grinding/growl. I would suspect an oscillating noise with the bend. I will think it over & make my decision in the morning. I'm now thinking it's the carrier & the bent axle was driven on by the previous owner & may have killed the carrier bearing. But I'll probably order a new axle & the rest of the bearings for the diff & pinion, & have them all installed (& the diff correctly adjusted) by my wife's uncle.