jaewonlee

Hi everyone! First time posting here...

My 09 C6 Z51 A6 recently developed a noise from the rear end (somewhere around the wheel). When I'm going over a slight bump very slowly, I hear some cricketing sound. It sounds as if an old door is creaking... like rusted metal hinges rubbing.
Based on the search here, it looked like an axle nut problem. Changed both sides w/ threadlocker red, torqued to 120 lbft. The original nut wasn't loose at all though. I'm still getting the noise!

I've already resolved other types of noises -- thump/clunking (changed sway bar end links), rubbing when turning hard in slow speed (flushed diff fluid). I can't seem to figure out where this one is coming from.
Any suggestions? I'll put my car on a proper lift next month for a shock change, and I was hoping to diagnose and fix this issue as well. Thanks in advance!

Corvette_Ed

Check your swaybar end links and bushings.

4SUMERZ

Since you have changed out most obvious causes, it may well be as simple as the exhaust moving causing that noise. It easy enough to push, and pull, sideways on the tail pipes and see if you can reproduce the noise. The other area may be the sway bar or shock bushings.
Good Luck
If you find the cause, post to help others in the future.

jaewonlee

Corvette_Ed: The end links are new. I'll check the bushings just in case.

4SUMERZ: Great point! I did have to loosen the exhaust a bit when replacing the evap solenoid. Maybe I didn't tighten it up well back then.
I'll definitely post the solution if I get to find it -- already got so many useful stuffs from here

BMF_C6

Check your jacking bolt pads, the rubber wears out and you can have a metal on metal on the control arms. The stock bolts have pads like shown in the pic below.

buckmeister2

Axle nuts??? Easy enough to check, or replace.

Dutch08

That's my guess.

Easy fix. (This is the way I did it, but it might not be the correct way.)

• Pull in the Driveway.
• Pull the center cover off the wheel
• Unscrew the large axle nut.
• Clean threads, add RED locktite
• Screw on a NEW AXLE NUT and torque to 140 ft-lbs (double check me here)
• Screw on the OLD AXLE NUT tighten.

Should take about 10 mins.

nplenzick

The clunking I had when going over bumps when driving slowly were sway bar ends links and bushings. Even though they looked and felt good when I took the old ones off and the clunking never came back with the new ones.

stingray71

Noise from your rear end? I think the jokes would write themselves on this one.

cgladish

i've been chasing for over a year now, a rear noise that i would describe as sounding like, an ice chest, half full of water & ice ( sloshing ).
it only happens in the cold ( temps below 60° or so ). above that, no sound. any bump will cause the sound. I'm pretty sure that I've changed out, all of the bushings i could.'
it has relatively new shocks, all new transaxle mounting bolts, leveling bolts.

please keep us posted on if you are able to figure it out. you have at least one person of interest here.

vetteJPJ

Same issues here. Did the axle nuts, no help. I'm afraid it's the wheel bearings. I've changed them several times. After a few thousand miles I get the noise back. What could cause the bearings to keep failing?

buckmeister2

Yes...but the first thing the OP should check are the axle nuts, as it is a 2-minute exercise, may 90 seconds. Most vette owners don't know what they are, or where they are. It is too easy not to do.

Have you found out why the bearings keep destructing? I assume you are replacing the hub and the bearings together, right?

torquetube

It is the first thing he checked.

Dutch08

Another guess then:

If perfectly good bearings keep failing then would check the rear tire toe-in and toe-out. If you have too much of either you increase the lateral loads on the bearing.

vetteJPJ

I guess its back to the alignment shop. Should I replace bearings first and then align?

torquetube

I'm skeptical that your bearings are failing. Changing wheel bearings requires a bunch of disassembly and reassembly. I suspect something tightened/moved during reassembly is coming loose.

As for axle nuts: instead of torquing them to the ends of the earth, try applying moly lube to the splines and to the flat at the base of the splines (requires partial retraction of the half-shaft from the wheel hub). The splines and the flat are the metal-to-metal interfaces that can make a click noise. The splines are not an interference fit, so there is some lash there. The only way to eliminate lash is with thrust force from the nut, which doesn't work great.

That said, I wouldn't describe the usual spline noises or wheel bearing noises as "cricketing" or "old door creaking". You and the OP may have something else wrong. Look at springs, shocks, anti-roll pillow blocks, and exhaust hangers.

vetteJPJ

I missed that the OP's noise was a clicking/creaking. Mine is more of rubbing sound. . I'll pull off the wheels and poke around to see if its something obvious( it rarely is). But we got snow yesterday and its 25 degrees out. I'll let the car sit until it warms back up. I'm in Arkansas so this cold is not the usual thing.

jaewonlee

Hey everyone, thanks for all the suggestions! For my case it was the exhaust -- metal rattling / cricketing sound going over a bump.


As you can see in the pic, in the middle of the car, there are two dual-springs (only 1 shown in the pic) that holds your exhaust.
I believe once the spring gets loose / elongates, it may develop noise -- from the spring itself, bolt, exhaust going up and down rubbing other metal parts (other bolts), ... who knows.

I asked my mechanic to add a zip tie to make extra tension and make it a bit more firm. He might have greased them too. Anyway the annoying noise is gone now!

FYI the other culprits for common noises
- Axle nuts: what I thought was the problem this case. Replaced.
- Sway bar end link (heavier thumping noise, not high pitched): replaced right after buying the car.
- Ride height adjustment bolt pads: mine looks ok, added some grease there just in case
- Rubbing noise: diff fluid flush, also done.

Hope this helps.