strong vibration/ chatter coming from rear wheels when turning slowly (2016 SHO PP)53K miles.

Hi Everyone,
I recently purchased a 2016 SHO PP package. I retired my 2015 SHO (145K miles) runs great, but wanted to get into something newer with less miles. I had the car for a week and im noticing when I back out of my driveway or parallel parking theres a strong vibration coming from the rear wheels, its a vibration/ wheel chatter. I dont feel anything in the sterring wheel, but only when i turn right or left do i feel it in the rear wheels. sometimes its stronger than other times, but always same strong vibration/ wheel chatter. I did some research and I might need to replace the PTU fluid and Diff fluid? But wanted to ask you all to see if anyone had the same problem and what ultimately was the issue. the car has 53,200 miles on it. Thanks in advance.

Changing the PTU fluid is always a good thing. I 100% would check the RDU fluid.

SM105K said:

Changing the PTU fluid is always a good thing. I 100% would check the RDU fluid.

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Thanks, Going to do both today and see how it feels after. Hoping its not something more major than that.

Another test you can do. Jack up one rear wheel, transmission in neutral, spin the wheel by hand, listen and feel for anything unusual.

Welp, I got an update. The guy at the shop unplugged soemthing that disconnected the AWD system so it basically operated as front wheel drive and took me for a drive in the car and the problem went away or almost 95% went away. So the guy said it was the rear diff that will need replacing unfortunately. Since this is the PP package ill need to source one thats the 3.16 gear ratio? Such a shame for a car that only has 53K miles. @Texas Marauder @SM105K. does that sound right to you guys? I was hoping for better news but this is what I got.

Greg_A said:

Welp, I got an update. The guy at the shop unplugged soemthing that disconnected the AWD system so it basically operated as front wheel drive and took me for a drive in the car and the problem went away or almost 95% went away. So the guy said it was the rear diff that will need replacing unfortunately. Since this is the PP package ill need to source one thats the 3.16 gear ratio? Such a shame for a car that only has 53K miles. @Texas Marauder @SM105K. does that sound right to you guys? I was hoping for better news but this is what I got.

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It really isn't common for a RDU to fail. We definitely see a bunch of PTU failures. Check out this thread below.

Greg_A said:

Welp, I got an update. The guy at the shop unplugged soemthing that disconnected the AWD system so it basically operated as front wheel drive and took me for a drive in the car and the problem went away or almost 95% went away. So the guy said it was the rear diff that will need replacing unfortunately. Since this is the PP package ill need to source one thats the 3.16 gear ratio? Such a shame for a car that only has 53K miles. @Texas Marauder @SM105K. does that sound right to you guys? I was hoping for better news but this is what I got.

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All RDU are the same. The final drive is determined in the transmission.

After replacement you need to update the Automatic Torque Coupling code. A 4 character code on a sticker on the RDU. The code is updated with a scan tool in the PCM.