Car is a 2004 coupe, 6spd, with 100,500 miles on it.

I've had a vibration that I've been trying to pin down for awhile now. My latest theory was either hub (bearings) or CV related, but I hadn't yet ordered anything because I couldn't figure it out. I was actually planning on ordering new front hubs tonight wince I could hear a click the other day out of the front left. Also worth noting is that I had what seemed to be louder than normal tire noise from the rear but thought it may have been the all season tires I put on there for winter.

So today I was on a one lane shared road less than a mile from my house and there was a car parked slightly on the road so I had to put the left two wheels into the grass/dirt. I was going no more than 10-15 mph and when I went onto the bumpy grass and pulled back on I all of a sudden had a terrible grinding noise from the left rear. I was on a hill so I proceeded to the bottom of it and parked the car to inspect. When I would come to a stop from only 5-10mph, with the clutch pushed in, the noise would persist for maybe a second or two after the car had fully stopped (sounded like rocks grinding on metal). No sound with the clutch out or in while stopped and a little rev so everything up through the transmission should be fine.

Anyway, after finding nothing horribly wrong I decided to continue the half mile or so home at 5-10mph. But after a minute or two the noise went away and never came back.

So I put it in the garage and jacked it up. Pulled on the wheels in all directions, put it in nuetral and spun them, and even ran the tires up to 15-20mph in the air. Left wheel looked like it may be a little wobbly while driving up in the air. Couldn't see right wheel as I was in the driver seat and no one else around.

Anyway, the only noise I could really get out of it was a sound in the diff as I spun the wheel back and forth. But they both spin together pretty well. Every once in awhile I can get a little click out of any of the wheels when pulling them at 3-9 or 12-6 oclock. Outter and inner tie rod ends have been replaced at all 4 corners already while chasing down the vibration.

I guess after all of that my only questions is - How do I know the problem is indeed the hub assembly and not the CV or Diff? These are not cheap parts so I'm not inclined to just replace all of the above.


The videos below aren't very good but should show you the sound from the diff when I rock the wheels back and forth in the first video. 2nd and 3rd videos probably don't show much due to poor lighting and crappy camera.

http://s246.photobucket.com/albums/g...t=P5140035.mp4

Driver Side
http://s246.photobucket.com/albums/g...t=P5140036.mp4

Passenger Side
http://s246.photobucket.com/albums/g...t=P5140037.mp4

 

I just read another thread somewhat similar to this one today... http://forums.corvetteforum.com/c5-t...hing-else.html

I can't watch the videos from where I am right now but from what you're saying I guess it might be a wheel bearing... Your wheel bearings should be making noise at ALL speeds not just when you're coming to a stop if they are in fact failing. How noticeable is the vibration and where are you feeling it? Try this; find a brick wall or a parked car or something big and solid that will reflect sound. Drive like you're going to pass the object on the side where you suspect the bearing has failed and before you reach it shut the engine off and coast by it slowly with the windows down. See if you hear any grinding/rubbing etc.

I wouldn't just keep throwing parts at it until you've isolated the problem though; it's not only a waste of money but it also adds potential variables that could further complicate the problem. Did your tie-rods have any play in them? Why did you replace the tie rod ends? Did you have any work done to the car before you noticed the vibration/grinding?

Another possibility is that your torque tube couplers are going. If they are you'll notice a vibration that gets stronger as the damage gets worse. Eventually you'll feel like you're constantly driving over rumble strips.

Also, just to eliminate a few other possibilities... What happens if:

Your car is in neutral and you rev it with the clutch out?
Neutral with the clutch in? Any Grinding/Vibration?
In Gear with the clutch in? Any Grinding/Vibration? Does the car try to move forward?
Driving slowly away from a stop? Any Grinding/Vibration? Getting louder or softer?
Coasting in gear with clutch out? Any Grinding/Vibration? Getting louder or softer?
Coasting gear with the clutch in? Any Grinding/Vibration? Getting louder or softer?
Turning the wheel far to the right and accelerating slowly? Any Grinding/Vibration?
Turning the wheel far to the left and accelerating slowly? Any Grinding/Vibration?
What are your RPMs doing when you hear the grinding/feel the vibration (are they falling steadily as you coast or is the tach "hanging")?

I really wouldn't recommend driving the car too far until you know what this is. If it is your TT couplers and they do fail completely you'll be looking at SERIOUS $$$$ to repair the damage it causes.

 

It is almost 100% certain your Torque tube couplers are shot! and especially being a MN6 and 100,500 miles on it -

They reside inside the Tube itself - not a very serious job to do but you might have to have a shop do the work with what is entailed to get it out from between the rear end and Bell Housing!

But rest assured it almost certain the TQ Tube bushings are junked!

Take a look at this recent article:
http://www.vetteweb.com/tech/vemp_12...ers/index.html

Thanks,Matt

 

Thanks for the quick replies guys. Even though it's my DD it's sitting in the garage on jackstands for now and I'm borrowing a car to go to work until this is straightened out.

To try to answer some of the questions...
I have done all of the above in your post cdkcorvette7 as this has been a problem I've been chasing for quite awhile but I don't get on the car hard at all so it hasn't really gotten any worse in the last 6 months to a year.

Here's some notable tests I've done lately. When I drive by barriers I DO hear a slight grinding but I only pass barriers on my right side so that's where I hear it from.

I've heard some grinding when I turn the wheels off the ground but it went away when I removed the rotors so couldn't fully blame it on anything for sure except the brakes dragging. However, the other day I heard a tick every time the wheel turned which is why I went back to thinking it was the hub assemblies. I was able to recreate it with the rotors off and wheel on so I was planning on ordering the front hubs this week. This was the front driver side btw.

As for the couplers in the torque tube, since it doesn't make any sort of noise with the car in neutral but clutch pedal out I don't think that is the issue.

The vibration is SPEED dependent, not RPM, but is there ALL of the time not just at certain speeds like with a rim/tire out of balance. With the car off and clutch pedal down the car still vibrates, and when crawling as in coming to a stop slowly it feels like a wheel gets hung up once every turn, like driving over a small bump. Again though, with engine off and torque tube not spinning this still occurs.

BTW, I got someone to drive it while it was on jackstands tonight while I watched and there is definitely a wobble to the driver side rear which is where my terrible grinding came from tonight.



As for the couplers definitely being shot because of the mileage - I've seen guys replace them at 30,000 and others who have had them chacked and still look great at over 300,000 so it seems to have a lot to do with how the car is drivin. I was planning on having mine inspected just to be safe whenever I eventually need a new clutch since a lot will already be apart.


I've spent well over 50 hours reading every thread on vibrations on the forum,a few times over, in the last 6 months. So I've checked a ton of things but never got a definite solution to the vibrations.

 

cdkcorvette7, the thread you linked to describes exactly my problems. I haven't been on the forum the last couple weeks as I'm getting settled in after a move.

Unless anyone says different, I'm going to be ordering new fronts and rear hub assemblies tomorrow. The vibration is in the steering wheel, seat, floorboard, shifter, literally everywhere. And I've got evidence to say both fronts and rears are bad because of the noise from both.

The terrible roads of DC and Virginia have really beat the hell out of the Vette over the last 4 months. It sure is nice to be back in smooth roaded Maryland now. I guess the bumpy brief offroad trip was the straw that broke the camels' back tonight for the driver side rear.

 

Well... If all that's true then I'd say you've found your problem. Usually best to replace wheel hubs/bearings in pairs per axle which it seems like you're planning to do. Not sure if there's any point in you replacing your front bearings as well but it's your call.

Replacing the rear hubs involves separating the rear ball joints so make sure you have the tools for that... This site has decent writeups on how it's done. http://www.jakelatham.com/C5/misc/ Some people prefer to use the pickle fork tool as is mentioned in the writeup, some people use a press designed specifically for separating ball joints and some people just hit it with a big hammer. Whatever method you choose take care to not damage the grease boots or the knuckles themselves as you'll then have an even bigger problem on your hands...

BTW, smart not driving it until it's fixed. If a bearing has failed to the point that it's vibrating as bad as your describing you definitely don't want it on the road.

Post here or send me a PM if you get stuck and I'll see if I can give you a hand. I had to replace the wheel bearings on my C5 at about 85K miles... This link is useful for torque specs http://www.eliteengineeringusa.com/C5_Torque_Values.pdf

 

If you don't find the noise, give us a call. We're not too far away.

 

I have worked with Rick before and would VERY highly recommend his shop if you decide to have this diagnosed and repaired professionally. You'd be hard pressed to find a better guy to work on your vette's driveline anywhere.

 

Will do. I've heard nothing but good things about you guys. Here's hopeing the hubs fix the issue though

 

Thanks for the kind words Chris.

Let us know if it doesn't. I can work around your schedule to diagnose the issue.

 

Rick x's 100!

 

Thanks Kevin!

 

Well I replaced the hub assemblies and the sway bar endlinks that were toast. The car handles AWESOME again... but vibration in steering wheel is still there. When lowering the front of the car down from a jacked position I hear a popping sound multiple times as pressure is being put back onto the wheels. I believe, but not 100% sure, that the sound is coming from the upper control arm bushings. So three questions:

1) Would bad upper control arm bushings cause a vibration?

2) Does it sound like I need to replace mine?

3) If it is determined they need to be replaced I DO NOT want to go the poly route as this is a DD that racks up 60+ miles per day and there's no way I'm going to take them out and regrease every few months. So where can I get non-polyurethane bushings?

And Rick, if I can't diagnose this within a few weeks I'm going to bring it up to you to check out for me. I'll PM or call you a week or so ahead of time to try to set something up.

 

Sounds good, give us a call.

 

Is that normal play in the wheel rotation?
Mine has brand new C6 posi clutches and belville springs and hardened shafts and is much tighter than that.

Ron

 

How much would be considered normal?

If there is extra play, what would it suggest there is an issue with?