I have a clunk/bang intermittent noise whenever I drive my car for a long period of time. I changed the differential fluid a month ago and the gears inside there looked fine,there wasn't really any pieces on the magnet inside the diff. case. I tooke the tire off and didn't see anything that may be the cause of the noise. I don't notice any other problems except for when I drive for long periods of time.Any ideas???Thanks

 

Shocks, lower control arms, torque arm. Check all of them for looseness.

 

Did you add the limited slip additive?

 

im betting on shocks, im having the same issue right now.

 

Don't have limited slip.I used the regular gear oil.

 

It's annoying,but only when I drive for awhile is when it does it??

 

What diff did you put in your car then?

 

Did you replace the stock diff? If not look for RPO code G80 - Axle Positraction, Limited Slip.

 

Unless he replaced it which I doubt he's got to have a LSD. In which case you NEED the additive it the geas will bind up and make a horrible clunking sound from the right rear area. I went through this on a customers V6 fbody. After seeing he had the Y87 package and that 2 weeks ago someone did axle seals for him I made a bet that there was no additive in it. I was right, have not seen the car since we added it.


Make SURE that you don't have a LSD

 

It is the factory differential that I have and I used 80w-90 gear lube. Do i have limited slip? How do I tell???

 

you better go get the gm additive from the dealer and add it ....

 

Should i change the fluid again since it's not synthetic or just add the additive? I was told that 80-w90 was the weight????

 

that weight is fine but YOU NEED THE ADDITIVE. you have a factory limited slip diff that MUST have the additive. Go to the dealer NOW and get the 4 ounce bottle and put it in.

 

Ok. Going to get the additive tomorrow. I am going to go ahead and put some 80-w90 synthetic in it while i'm under there. I hope that this will fix that annoying noise.

 

I meant to post a couple days ago. I changed the lube added the additive,now it's quiet.Thanks for the info guys.