I have searched here and youtube and have not seen/heard of my "noise". I just came into possession of 2000 C5 Targa manual with 52K. I am 6th owner. The previouse owner is good friend who had it 6 years and 16K.

I asked him about this noise and he did not hear it until we turned off radio and went easy on peddle (to reduce custom exhaust noise). Basically it is a clunk, sort of like a shock bouncing around in a shock tower (the shocks are tight,

with no sign of leakage and the noise does not "rattle" like a loose shock would). It is a definite clunk, not "tinny" like sheet metal or a heat shield. If you take off easy you do not hear it. Normal takeoff you do. If you're just cruising

15-20mph, not on the gas, the noise happens randomly. It sounds like it is coming from over the driver's right shoulder and the passenge's left. So I jacked rear up and checked bearings both side, and they seem ok, Do not see any

play in the axle shafts. With right rear jacked up and car not in gear, rotated right tire, and it rotates maybe an inch. Did same to left and got more like 1/5-2 inches rotation. And holding a screwdriver to diff while rotating the left wheel

back and forth, heard the noise in the diff. A web search led to a youtube video where tuber shows the wear in the teeth of the friction plates in the diff clutch packs for a similar C5 diff. It showed whatI I felt was the amount of play that

would lead to the left wheel rotation. Since I do not know how previous owners drove I decided to drop diff and replace clutch packs. Once diff was opened, I found that the clutch packs look good with no play at all of friction plates on

splines. The bearings in the diff look good, and the pinoin gear is solid. So I have put the diff back together but am hesitant to put it back into car without knowing where the noise/play is coming from. It was suggested to put everything

back and test the control arm bushings, but the play and noise was evident from an unloaded wheel. And the noise occurs regardless of which gear your in.


Thoughts/ideas?


Paul

 

If the noise is loud enough to hear when the car is moving I wouldn’t think you would need to use a screwdriver to hear it when testing. My first thought based on your description is the differential mount being bad. During hard take off it loads up quickly and you don’t hear the clunk over the exhaust. When taking off lightly you don’t torque the drivetrain enough to induce the rotation required to make the noise. Normal take off causes the driveline to twist and knock something because of a bad mount.

There could also be a problem with a drive shaft coupler or bearing inside the torque tube. I’ve seem carrier bearings fail on two piece driveshafts that induce a similar sound.

Either of these two could also make noise when driving based on minor road changes or throttle inputs.

These are my best two guesses.

 

Call Rick T Kim, He is a forum vendor, RTK is his business and he specializes in rebuilding/upgrading differentials. He maybe can give you some troubleshooting pointers on your diff. If you think it needs proper setup or repair, he is a good resource.

 

hes a great guy helped me plenty of time. did not take up much of his time because he knew right away what was wrong.

 

Maybe this will help since the car is apart
https://www.corvetteforum.com/forums...ing-noise.html
Did you actually take the clutch packs apart and look to see if the belleville washers were broken?

 

two possibilities that might give a Popping sound, the sway bar bushings and not enough friction modifier in the diff fluid. AC delco has a pre-mixed diff fluid with the FM already added. Best price on Amazon. Take the center bracketed off, remove the bushings.They have a split in them I clean them up and add a little silicone grease. Also if the sway bar is rusty where the bushing is, sand it to bright metal.

 

Yes did pull the clutch packs and the belleville are ok.

 

Thinking it might be torque tube as well BUT then would expect the issue to be equal across the two wheels and
there is definitely more play in the left wheel.

CORR: rotation of left wheel was 1-1/2 to 2 inches
CORR: using screwdriver isolated the noise to the diff.

 

If diff backlash is setup properly should there be any noise/play from diff???

Here is what I'm hearing when I rotate the diff minutely.

https://photos.app.goo.gl/avv4S58JsPhrzG5j9

 

I just went a check mine i have zero movement. I think u found your problem.

 

UPDATE:
Went to see RTK. Talked about possible causes, I decided to go with diff rebuild 1) hoping it would fix noise and 2) to put 3.90 gears in! Unfortunately it did not fix noise. But what a sweet difference!
So further research with the noise increasing eventually showed that the right rear CV was going. Replaced half shaft and noise is gone! Shout out to PartsGeek.com. Ordered part on Tuesday afternoon, standard shipping had it to me Wednesday before 1pm. And installed by 3:30!!