Weird vibration

**kmassner** · 10-09-2012, 09:11 AM

So, I developed a weird vibration from the left rear. Makes a rrrr-rrr when driving, directly correlated to speed. Sounded like an out of balance tire, except a slight metallic sound I can hear with the window down, when hugging the concrete barriers.

So, I did:
Rebalanced tires, rotated, made sure rims were true.
Brake job, new rotors out back.
New shocks in back (needed them anyway).

Still doing it. It's loud enough at road speeds to lull children to sleep (I notice).

Definitely left rear wheel well area.

I'm running out of ideas. Anyone?

**Smittro** · 10-09-2012, 11:16 AM

Could be an axle bearing dieing.

Deep pothole or a curb shot could have damaged one or the other or both axle and bearing.

Check your gear oil level.

Did you have your parking brake shoes changed too?

**kmassner** · 10-09-2012, 11:40 AM

Hmm. Will look into bearing. Good thought. I was running out of moving parts to change. I'll check the oil level too, but why would it be only left side?

Nah, haven't done parking break shoes.

Thanks!

**Smittro** · 10-09-2012, 01:54 PM

That's just how it is usually.

If an outer axle bearing goes out it's usually one or the other bearing that goes.

I have yet to see both outer bearings fail at once.

Can be a number of causes really, from the things I listed earlier to even axle hop, etc.

The f-body 10-bolt just is'nt that great of a unit to begin with, even little 3800 v6's can kill one.

**kmassner** · 10-09-2012, 02:02 PM

Probably had some hopping going on because the shocks were completely shot. I'm sure that didn't help.

I've had the car a while, never replaced them (I **ASSUMED** the previous owner did). Its been on my list for a couple of years.

Imagine my surprise to see those stupid orange DeCarbons. Guess they have 125K on them. Rediculous.

Yeah, I know about the 10 bolt. A 9 inch isn't in the budget right now though. Eventually, as I have no intentions of ever getting rid of the car.

Anyway, got a quote of about $400 to do both sides.

**Smittro** · 10-09-2012, 02:42 PM

Just be sure that's what the problem is before your throw money at it.

Hate to see folks have to throw good money after bad..

I hear you on the DeCarbon dampers.. They are'nt/were'nt that good new..lol

I hated them on my 01 Camaro..

**35th-ANV-SS** · 10-09-2012, 03:02 PM

You can also check to make sure the caliper is not sticking on that side. Are the brakes hot on that side after a short drive?

If you jack the car up and rotate the tire, can you replicate the noise?

**Smittro** · 10-09-2012, 05:10 PM

I also agree with Jon.. Those calipar pins can get rust frozen an cause all sorts of issues.

Even if they are'nt stuck solid if dry they can cause the calpar to hang, even cause uneven pad wear.

Good catch Jon!

**kmassner** · 10-09-2012, 05:12 PM

I've had the brakes done since the noise started. Worth a look, but we don't get weather often.

**cammed goat** · 10-09-2012, 07:37 PM

Keep us posted on your findings.

**kmassner** · 10-19-2012, 01:14 PM

So, it was indeed the axle bearing. As a bonus, as the bearing got more worn out, it jacked up the axle. So, this project got more expensive than originally anticipated. Dammit.

**Smittro** · 10-19-2012, 09:34 PM

Yeah, they can do that. Usually wipes out the bearing race on the axle.

I seen them fuse the inner bearing race to the axle shaft, and some where what was left of the bearing had worn a deep groove into the shaft too.

Sucks man sorry..