Skip the auto shop - Our mechanics make house calls

Q: Knocking/fluttering in rear end

asked by on

I have a 2010 GMC Acadia. Last Friday my car didn't feel right. Thought I had a flat because of the fluttering sound in my rear end. Later that morning I Ended up getting a flat and a screw in the other tire (both passenger side.) they plugged the front and replaced the rear pass. No more noise. Fast forward to this Friday night noise is back as is a clunking sound. Took it to get looked at. Suspension is all good. They suggested could be the drivers rear tire is so different in tread depth that it is tricking the speed sensor to fool the rear differential. They suggested I change the rear tire and that should fix it. Asked if I was doing any further damage driving it. They said no. I drove it home yesterday and out today around town. Fluttering is worse and noisier. I'm sure it has something to do with the rear diff from everything I have read. So my question is... Any suggestion of next step? Will tire make that much of a difference? I have owned the car since 88000 and have no record

My car has 112000 miles.
My car has an automatic transmission.

Hi and thanks for contacting YourMechanic. If you have a limited slip differential, then having 2 different size tires on the axle will cause the limited slip differential to make this noise. Eventually, the limited slip will stop working and your vehicle will then drive normal with burnt clutch material in the differential oil. I suggest putting the odd size tire on the front of the vehicle and putting a regular size tire on the rear. If you would like to have another local expert inspect the car in person, a qualified professional from YourMechanic can come to your car’s location to pinpoint the proper fix.

Was this answer helpful?

Need advice from certified mechanic? Get help now!

Over 1000 mechanics are ready to answer your question.
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details
  1. Home
  2. Questions
  3. Knocking/fluttering in rear end

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Fair and transparent pricing

Get a quote

What others are asking

Q: Wheels lock up and have to cool down before driving again.

Hi, If you have had a brake master cylinder or brake booster installed recently the problem may be due to the installer not adjusting the push rod on the brake booster. The push rod may be pushing on the master...

Q: Cranks but does not start.

Hi there. Check the battery on the vehicle and make sure that it has enough voltage to start the vehicle. If the vehicle is cranking up and it sounds as it is about to start but it does not start,...

Q: New battery now car won't start but with old battery it did start.

The anti-theft system has been activated and if you turn on the ignition and see the theft light on or blinking then it is active and may need to be scanned using a dealer level or equal scanner that is...

Related articles

P0052 OBD-II Trouble Code: HO2S Heater Control Circuit High (Bank 2 Sensor 1)
P0052 code definition HO2S Heater Control Circuit High (Bank 2 Sensor 1) What the...
What are the Car Pool Rules in Hawaii?
Hawaii is widely regarded as a land of vacation and relaxation, and as such, its scenic roads and routes are far better known than the state’s freeways. But, as with all...
P2428 OBD-II Trouble Code: Exhaust Gas Temperature Too High Bank 1
P2428 code definition A P2428 trouble code signifies that the PCM has detected a problem in the exhaust gas temperature sensor circuit in bank 1, which subsequently contains the number one...