Is it the rear differential?
 

Just had mu Audi 2001 A6 2.8 serviced. Tires rotated ,hepa filter etc. It has 149,000kil. When I drove it home I noticed when I was in slow traffic and almost stopped there was a vibration.Brakes have all been replaced and in good shape
Took it back the next day. the dealer said since the tires had been rotated and were worn it was probably coming from that. I replaced the tires. The noise still there. The dealer checked again and said the rear differential probably needed to be replaced. 7,000 dollars. I love my car and it's in great shape but not worth putting that much money into. Took it to a european car specialist. He doesn't think that is the problem but said there is a bit more play then should be?

It is not a loud noise at all. It just doesn't sound as smooth running when you slow to a stop. It is not anything to do with the engine. If I continue to drive will I have lots of warning when the differential does go?
Thanks for any help

Re: Is it the rear differential?
 

i doubt you have to change your differential... check out some other opinions...

Re: Is it the rear differential?
 

coil pack?

Re: Is it the rear differential?
 

Best advise, if the dealer is too happy to spend lots of your money on wild ass guesses, then never go back there. Find a reputable independent Audi garage that will actually diagnose the problem properly and give you a proper estimate. there's lots of things that can cause a mild vibration- wheel bearing, suspension links, bushings, brake/fuel lines, heat shields, engine/transmission mounts and other powertrain issues, even a loose exhaust/ muffler mount. Most powertrain problems get much louder as you go faster, including worn wheel bearings, so that doesn't sound like it the cause, but either way you have to have a knowledgeable mechanic have a go at it, all we can do here is give you more wild-ass guesses!

Re: Is it the rear differential?
 

Thank you for your common sense answer. I am sure you are bang on. We made our trip to the southwest with no problem. I took it in to a independent Audi specialist down here. He was with Audi for 35 years. He drove the car and said it is definitely not the differential. He did not hear the noise but like you said it could be a number of things. I will check out the muffler exhaust possibility. I only hear the noise occasionally but was concerned it might be a major deal.
Thanks again
emlee