Praetorian27

And no...I didn't eat Mexican food recently! There is a sound coming from the rear of my '99 convertible 6 speed that has 53k miles on it and is bone stock. It sounds more like a growl than a whine or a grinding noise. It happens when going in straight lines as well as turning, so I don't think it's a wheel bearing. It does it when under power, as well as coasting. The sound doesn't come and go...it's there all the time. Also, the car has a hard time staying in reverse. I can shift into reverse, and start moving...but it will very frequently jump out of gear and the teeth with start grinding. If I keep gentle pressure on the shifter, pushing it forward into the reverse position, then it's never a problem. Are these problems related? I have no idea how to start looking for what could be wrong...any tips to get me in the right direction?

Earl T Patterson

I have a 2001 roadster with a 6 speed which has developed the growl. I find that if I turn to the right, it goes away, but going straight or turning left it growls. I am glad to find I am not the only one with this problem. But I do not know what is causing the growl

Praetorian27

I have read a lot of threads where the growl seems to be a wheel bearing. This sound is deeper than a typical wheel bearing noise.

Praetorian27

Anyone else?

dgrant3830

Do your tires have any cupping on them?

n8dogg

growl is typically a wheel bearing and gets worse with speed. Will change noises when you turn left or right as well.

Praetorian27

No, though I'm not super confident I understand what cupping is. But from what I have read, there are no uneven scallops that catch when you slide your hand over the tread.

Praetorian27

It sounds deeper than typical wheel bearing noise from my experience...and the sound stays the same whether I am driving straight, or turning...under power, or coasting with the clutch in. It never seems to change pitch very much. Obviously lowers in tone when you are going slower though.

loneagle

You might want to think about changing differential fluid and if you do don't forget to add the limited slip fluid. I have an '02 and just did it. I had no noises but the book says to change at 60,000 mi. I also had a wheel bearing go out on me but I had a whine and it changed pitch at various speeds. They are sealed bearings and come as an expensive unit (250-300 bucks) not installed, you can get cheaper but there made in China and you buy cheap and you get cheap besides you don't want to put a chinese part on an AMERICAN car.

Praetorian27

Wouldn't a wheel bearing make more noise depending on your turn direction? I have always known a wheel bearing was going by swerving back and forth and seeing when the noise was loud, and when it was quiet. I am going to change diff fluid and see what happens. Any advice on the fluid? It is supposed to be Dexron 3 right?

jsbzoh6

You prefer Mexico, I guess? I don't think you realise entirely how much foreign country made parts we all have on our cars. What tires do you run? Probably not made in America.

If its a wheel bearing it will change with the direction you turn. Autozone has Timken bearings for around 160$ and they work very well. I have two on the back of my '00 and have no issues. Others on the forum will say the same.

To me, your problem sounds like differential. Mine developed a whine that started at around 28MPH and went from low-pitched roar/growl and got progressively louder as the speed went higher. The only controlling factor was speed, nothing else. It also happened under throttle or coasting, there was no change in condition.

jsbzoh6

Transmission fluid is Dexron 3. The diff fluid is 75W-90 gear oil. I used Mobil 1 synthetic from Autozone, you'll need 2 bottles. You also need atleast one bottle of the LSD additive from the dealer.

dgrant3830

Your description is correct. I mentioned it because some years ago, I was having a deep grinding type sound going around a right turn near where I lived. I replaced both rear wheel bearings which didn't fix the sound. I then drained the rear end fluid, finding only about half a quart inside where it should have had 1.6 qts. I refilled with the 75W-90 and the proper GM friction modifier but the grinding remained...but just going around the one right turn.

I went to the dealer whom I trust highly, talking and so on, I elected to purchase and install a brand new differential at $1898. Going home from work that night, same turn, same noise, still present.

About a week later, I was at America's Tire Company and this other Corvette owner was changing wheels and tires off his car. I bought his GY DS-3's and chrome wheels, all in good shape as my tires had lots of cupping on them. That night, same corner, no noise and none ever since. It was the tires in my case. Do not run out and buy tires for your's as your's could easily be something else. You need to follow Bill or Lucky's thoughts.

loneagle

Your right about some foreign parts but I had no control over those when the car was built I do when I buy in America and try to do my part by buying American when I can. I would bet that you would not find those parts in the motor more on interior stuff etc.
As for the bearing I changed the oil first still had the whine just as you described but disappeared when I changed the bearing about a 1,000 milles ago. PS I run Goodyears...

cdkcorvette7

There's a bear under your car and he's pi$$ed.

Seriously though; sounds like two separate issues. "Growling" from one corner is almost always a wheel bearing. Metal-to-metal on the brakes can also produce a growling sound. To check the wheel bearing jack the wheel up, grab it, and jerk it from side to side. If there's any play you likely have a bad wheel bearing.

The transmission popping out of reverse is a pretty common issue. First thing to check is your shifter alignment. If that doesn't solve your problem you're going to need to have your transmission torn down and rebuilt. The problem will get worse eventually if it's an internal transmission issue... Ask me how I know.

Contact Rick at RKT56 for more info and for a quote. You absolutely cannot beat his work quality and prices. He's awesome to work with.

loneagle

I used GM's 75W-90 Part #GM 89021677 2qts.

Limited Slip additive Part# GM 1052358 1qt.

Sully1882

on my 2000 coupe with A4 auto the rear wheel bearing went bad and the noise was centered inside the car.... driving on the interstate was LOUD. One shop said it was the rear end and another said the wheel bearings. CHanged the bearings and all was good since.

hth,

Sully

Rick@RKT Performance

From what you describe here, I would rule out the drivetrain. I would guess a bearing. If you take the drive down, I'll be more than happy to find out where the noise is coming from.

The reverse is another issue but as cdkcorvette7 has stated, try the shifter alignment first.

Thanks Chris!

rws.1

I have a similar issue just starting to develop and am sure it is the rear passenger side wheel bearing...
I will be replacing it with a Timken (brand) bearing.....

C5kid

had a similar issue, thought it was the rear, turned out to be drivers side wheel bearing.

it would growl in throttle, coasting, turning, straight line, etc. jack the car up and if you can pull out a cv joint and spin the bearing