Cadillac CTS-V - Vibration and a thud. Rearend

So i have an 05 v. The rearend seal was leaking, this past month. So i took it by the local chevy dealership
GM paid for the part, but i had to pay gor labor. Thats fine what ever. They fix it. Then i get back to the house and while turning at low speeds going forwards or backwards, a vibration and thud or rubbing sound emits from the rear. Called the dealer and they take a look and said $1,200 for the rearend clutch. I asked to talk with the mechanic and he told me that i didnt need to change it, that it would be more of a nuisance than something that needed to be fix.

I have a headache. So id figure id share this to get you' ll thoughts.
thanks guys

He's probably trying to tell you that you're better off buying a new diff... Tough call it's not something you can ignore

Well I asked him straight up if this needed to be replaced or what? He told me it was nothing to worry about. oh well, going to have someone else to look at it.

The diff fluid is supposed to have a friction modifier added to it. Without it the LSD is really grabby and makes kind of a "wub wub wub" noise/vibration during low speed turns.

Mine had that when I first bought it. I was still under warranty, but I found a thread about it on here or CF. Anyhow, they flushed the fluid and added the friction modifier and all was well.

If anyone asks, just tell them you put in a welded diff. from a 240 ;)

-meaty

The diff fluid is supposed to have a friction modifier added to it. Without it the LSD is really grabby and makes kind of a "wub wub wub" noise/vibration during low speed turns.



X2

Tech forgot to put in the modifier.

Awesome. Thanks guys.