LAST UPDATE (2014.03.29):




OLD UPDATE(2014.03.23):

Thank God for spring break. So I manned-TFU and bought a 12-ton press from Harbor Freight. Picked up new bearings and hubs. I took everything apart, cleaned, and swapped in new parts.

No more noise, smooth ride, no pull left or right during acceleration. Problem solved.

The bearing and hub on the driver side rear was completely trashed. When I pulled the knuckle away from the axle, black carbon ash poured out of the bearing all over the ground. I took a picture of the hub; the damage was gnarly. I'll be sure to post it later when I have time.

Thanks for all the input guys. I have little time these days and you helped me use my time effectively.



OLD UPDATE (2014.03.09):

So yeah, 18 credit hours in Engineering and kid on the way have left me pretty low on free time. Anyways I finally threw the S up on jackstands. I took the wheels, axle nut, calipers, and rotors off.

Well... safe to say I found my problem.

I took the axle nut off the driver's side (where the noise has been coming from) First thing I notice? Um, wow that nut came off easily (only about 100 - 120 lb-ft of force applied, TOPS) Second thing I notice? Rust powder... oh sh**. Well really how bad could it be, right? Well I get the caliper and rotor off. Hey guess what? I can wiggle the hub around. EASILY 15+ degrees deviation in any direction from what should be "straight" The hub is basically a video game joystick there is so much play in it. So I'm gonna take it all apart and hopefully the destruction has been isolated to the bearing... otherwise.. new axles? new cv joints?

Well it's gonna take me a while longer to get the car back into service, at least I didn't have anything shear or snap at cruising speeds.

OLD:

So I could use some help diagnosing my s2k. I could ask in one of the tech forums, but I know you guys, so I trust your opinions.

I've had a grinding/scraping noise from the left rear that started quietly and very sporadic about 2 months ago. Over time it grew to be constant, the scraping is in time with the rotation of the axle/wheel. I initially just thought it was the brake pad and was going to replace it this weekend. But, two days ago I loud clunking or banging noise developed from approximately the differential (what it sounds like INSIDE the car). I drove it straight home, and hard parked it. I'm not moving it until I can figure out what it is.

Stuff that MIGHT be related??

-About a month ago (after the noise started) I had an alignment, the left rear wheel was off, but the right rear was perfect. Just prior to the alignment, sudden acceleration in 3rd gear at highway speed would cause the car to pull right, braking would cause the car to pull left (tires were all equally inflated). After the alignment it seemed fine. A week ago the exact same problem showed up again, but only sporadically.

-At highway speeds 60+ I would experience occasional vibration that would last for a couple of miles. I can only describe it as a side-to-side "shimmy" but without causing any body roll or swerving in the vehicle.

I'm stuck driving my other cars until I can figure this out. I can fix it if I know what direction to head, what to look it, what to rule out. But I'm really stuck, I don't know what to start with. Any suggestions?

 

Is your car stock? Specifically height adjustment

 

It could be something as small as the wear indicators on your pads to rusted axles to bad wheel bearing/s.

Here are a few links to similar problems and what they're solutions were. One of them has videos. Hopefully theses will guide you in the right direction.

Similar noise thread

Similar thread with videos

 

Yep, nearly 100% stock. Only modifications are a 4 stage body mod I've implemented with different tools:

Stage 1 - curb
Stage 2 - trees&boulder
Stage 3 - Ford Explorer
Stage 4 - Ford Escape


Thanks for the links man, I'm gonna start poking around and see if I can isolate this problem. Really worried and frustrated.

 

Let me know what you find. I'm having the scraping noise in the same location...but i'm still in the "quiet" stage. I also hear a clunking sound in the back, but I'm not sure if it's related...or even the same as you're hearing (i thought i had pinpointed this sound to one of the clips in the trunk area).

Keep us posted.

 

When I was locating which wheel bearing was bad in my car, I drove it on curves going left/right and listened carefully for when it got louder in each direction. Left turn: weight is distributed to the right. Right turn: weight on left. My noise got louder when I would take a left turn and it was the passenger rear wheel bearing I replaced. Another thing I did was jack the car up and spun the wheel while I had my hand on the spring to feel any vibrations from a bad wheel bearing.

Here's a video of the noise I had. Bad Wheel Bearing noise

 

Well first thing I'm going to do is replace the rear pads and rotors. Pads are well worn anyways, so they need replacing. The left rotor upon visual inspection might be warped. I don't know if this is 100% of the problem, but I want to eliminate it as the problem. I'm going to ensure calipers et. al. are properly lubed. If there is still noise at least we can rule out those basic things. I'll let you guys know what happens. Thanks for all the input so far.

 

I bet on a wheel bearing.

 

Yeah my first thought was wheel bearing too. Have you jacked it up and checked for movement in the bearings? Turned the wheels/hubs by hand to see if you can locate the noise?

Does the noise stop if you step on the brakes lightly?

 

That's what's weird, I can't replicate the noise with the back end lifted. I even tried lifting both sides of the rear and (crazy I know) turning the car on and accelerating in gear. I can't reproduce it on stands. It disappears when accelerating hard and it's most noticeable when the car is rolling in neutral. Right turns are louder than left. I've heard some scraping when going over speed bumps, but there is nothing visually that stands out.

Also there is no noticeable change when braking, hard or soft, the sound is dependent on engine load. Loudest when tranny is neutral, quietest when accelerating, harder = quieter. Recently (when I stopped driving the car) sudden lifting of the accelerator would produce a clank sound, mostly in 1st and 2nd.

As I start disassembling everything I'm going to check for fitment/play of everything connected back there.

Driving me crazy