bigcypress

yes , i did a search but found less than anticipated and much extraneous info . car is really strange backing out of garage but don't feel i can accurately describe ''strange'' . when driving car yesterday i was in some very quiet areas and realized i was getting a noise when turning . car is 2004 vert purchased about 3 years ago from a dealer about 102 miles south of us . i'm sure we were told all fluids had been changed . the car was delivered to us on a trailer . we noticed very similar noise immediately upon driving car . took car to a local dealer and had fluid changed , mileage was 28,987 and cost about $132 . car now has 29,960 and i don't know what to do next . all thoughts appreciated . . . peace .....ps. seller was a nice man [i think] but i would not buy from him again .

caddman11

I have a strange noise to which i tried to describe here, I'm pretty sure the responses are correct. I have my mechanic looking tomorrow and then I'll know for sure. https://www.corvetteforum.com/forums/c5-general/3848899-rear-end-noise-starts-at-20-mph-new-post.html

bigcypress

still have noise especially when backing out of garage at which time i can here loud noise and also FEEL a severe ''shuddering'' sensation . car now has about 30,065 miles on it or about 1078 since diff fluid was changed . could ''problem'' be something else . last time i drove it i also stopped in a lot and drive little circles for about five minutes which was suggested some place . i'd appreciate any suggestions and , incidentally , the ''link'' from previous poster didn't work for me , unfortunately . . . . peace

El original

The only thing that comes to mind are wheel bearings...

David Shiel

Other possibilities:
1. No or wrong additive with differential change. Clutches binding as a result.
2. Parking brake hung up

3.Wheel bearings and half-shaft joints are a stretch at this low mileage. That is unless it was abused.

My 01 was making a bit of noise and my local , really good tire store, dx'd as no additive. Put it in and away I went.

bigcypress

i've still had noise so it spent a couple days at dealer . assistant service manager drove it about 30 miles and says the noise is better [less] and driving it home a few miles i'd say he is right but will know better next time i back it out of garage . they checked the things you folks suggested and are sure noise is from differential . a couple of times i had driven it in tiny circles in a lot as some one suggested with zero change in noise and dizzyness in my head . by the way last time i did that the dash read '' traction control warming up '' and after i left lot it said '' traction control warm'' . i didn't know if that was good or bad and service department had never heard of this before . i meant to read manual but forgot , i'm old and forget OFTEN which sometimes saves me a lot of work as i forget what it was when i go out to do it . . . . peace....edit : just did a search and read about traction control , all is well there .

El original

Did you try and post on C5 Tech section...we only like to comment on tires and waxes here

bigcypress

so here we are nine months and about 300 miles later and car is exactly the same with no improvement . took it back to local dealer yesterday and their corvette expert says it is clutches binding and it just needs to be driven more . wife's other vette a 2000 with almost 40,000 miles gets driven less and does not have the same symptoms . the 2000 had all fluids changed to some kind of ''purple'' [royal purple maybe??] just before we bought it 11 years ago . i'm thinking about switching to the amsoil i've read about here which means another bill for fluid change . i'm concerned that A] it can't be good for and has to be wearing excessively on the ''clutches'' in dif , B] we good never sell it with it making this noise . we wouldn't have bought it had we driven it first but salesman at buds wouldn't let us drive it unless we bought it . first time we heard it was when delivery guy backed it off his truck . thanks for your patience . . peace

3sACROWD

The traction warming up is not an issue. Your car will go into this mode if you start turning shortly after starting the car and before it completes it's internal checks. The car needs to be going straight for some period of time before the check will complete.

Still sounds to me that the clutches in the diff are your issue. If you are planning another potential diff fluid change, I would put some additional additive into your diff and see if it helps.

Also, try jacking one rear wheel off the ground and turning the wheel by hand. It should take a decent amount of force to turn the wheel (I think it is 100 ft lbs). Then do the same on the other side. Do they feel the same or different? (Make sure the trans is in neutral and parking brake is off.).

If the wheel turns easily, you have a bad clutch pack or broken belleville washer(s).

Keith Richards

Sorry you are having issue's, my '99 Chevy 1/2 ton developed a horrendous noise and with 230k on the clock figured the rear differential gears were gone but just needed new fluid as the friction modifier had actually worn out in the 50k miles since last changed, that being said but I would NEVER buy without driving first unless a new car

killian96ss

Sounds like the fluid that was put in didn't have enough friction modifier. Some rear end fluids already have the additive while others dont. If there isn't enough you will get strange noises like popping, banging, shuddering, etc. The sound is the clutch plates locking and unlocking abruptly instead of just slipping like they should.

Replace the rear end oil with an oil that has friction modifier in it or if you use oil without it, you can purchase a small bottle of the modifier and add a little at a time until the noise goes away.

Steve

bigcypress

thanks for your replies . i forgot to mention , when dealer called back and said i just need to drive more i suggested adding a little more of the additive , like an ounce , to see what that did to noise . he said it can't be done , you either replace all or leave ir alone . i don't see why this would be so and in fact i think i've read on here of people doing it . . . peace

3sACROWD

The dealership is full of beans. You can buy a small bottle of additive. You may have to remove some fluid so you can add the additive. Use a turkey baster type syringe to remove some fluid.

BroncoBill

I had a weird noise I thought was coming from the differential or tranny. It was like a clicking/vibrating sound. Took it in to my Mechanic's house to have a look. We took it for a drive and when we got back to his house, he reached up between the exhaust in the rear where he flicked the pretty chrome corvette emblem plate mounted between the exhaust. Sounded a hell of a lot like the noise I heard when I turned corners and under certain exceleration. He tightened the bolts on it and I haven't heard a peep since. Just thought I'd share in case that might be the case with yours.
Bill

BADBIRDCAGE

Sounds familiar. Had a noise issue with my 2000. Making a hard left turn, especially when cold, produced a creaking, shuddering, grinding type noise in the right rear quadrant. I had changed the bearing hub assemblies less than a thousand miles prior to the initiation of the noise. Thought it might be half shaft/CV joint. New fluid and additive had been added to the diff at the same time bearing hub was installed. Took it to the dealer.

Dealer said noise was posi unit clutches binding, transferring noise through halfshaft to bearing assembly and recommended fluid and additive change, said there was a newly developed GM additive and said the noise would go away within 500 miles. $112.00.

I said OK, what's to lose. Picked up car. Noise was gone. Had the car another three years and never heard the noise again.

I.B.Sorgn

Vetteman Jack

I.B.Sorgn

I have a creaking grinding noise which is coming from the rear of the car. I've had 3 folks look at it but can't put their finger on what the problem is. Only makes noise when I turn, even a little turn at speeds as slow as a couple of mph. Almost sounds like a metal on metal noise. I was starting to think about the posi trac components too. Never get noise when going straight only when turning but have not notice a shuddering sound. To be clear, your differential oil was drained and replace and a friction additive was added? Can you tell me what was used as this could be my problem.
Appreciate your reply. .

I.B.Sorgn

In reading all of the post here I decided that the noises described were in fact the same noises my car is generating. Maybe at a little different time and speed and load but essentially the same. I decided to drain the diff fluid to see what might be floating around and found a number of brownish chips (very small, size of a tip of a pencil) and also found gold colored flakes so small they could not be felt. My best guess is the chips may be material from the clutch discs. The flakes, I'm guessing, maybe from something brass in nature! I could not decide if these materials are signs of things going south or just normal wear. I'm guessing that, because the material was so small in size and very little in quantity that it was normal. I then replaced the gear oil with Lucas 75w-90 synthetic and added 4oz of friction modifier. Took the car out for a drive and the squeaking/creaking noises left within a matter of minutes. Today I drove over 200 miles and all is well. I believe that the problem was no friction modifier in the oil which caused the clutch discs to bind and slip anytime one wheel was turning faster than the other ie., turning the front wheels and in my case even a couple of degrees. Have to thank the good Lord on this one as I thought I was looking down the barrel of $,$$$ in repair costs. I have kept a sample of the old oil and pieces of debris and will ask some of my more knowledgeable motor-heads what they think, but at least I know the problem is in the diff and most likely the clutch discs should repairs be necessary. No more scratching my head!..

I.B.Sorgn

Judging by your reply it appears you did not read my entire post as I documented the solution and all is well after 2 years