Howl from driveshaft or rearaxle when decelerating from 55mph-45mph? (details inside)

Discussion in 'SRT Hellcat General Discussions' started by srtjay, Jul 5, 2016.

  1. srtjay

    srtjay Active Hellcat Member

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    New to the A8 and the 392, so wondering if this sound is normal or unusual. Car is a 2016 Charger SRT 392.

    If I let off the gas from around 55mph, there will be a fairly audible gear-like whine/howl from some component of the drivetrain, most likely either the driveshaft or the rear axle, that goes away immediately if I put my foot back on the gas pedal at any point, or if the speed goes below about 45mph.

    If I flick the stick over to manual mode, it shows the car is in 6th gear when this is happening. It happens in automatic mode too, which is the mode the car is most often in.

    Car is in Custom drive mode, which is set up for pretty much all Street settings except for the trans set to Sport, but it also makes the sound with the trans set to Street.

    Car has under 200 miles on it and has done it since the first time I drove it home.

    As far as loudness, I can have the radio between 8-9 volume level (stock Alpine system not upgraded) and can easily hear the noise over that.

    I tried to record it but the mic doesn't pick it up well over the engine sounds.

    Just curious if this is a "yeah that's normal for the A8/392, nothing to be concerned with" or a "no, not normal and I got it fixed" or "no, mine has no perceptible howl or whine when I let off the gas and let the engine brake at those speeds".

    I asked on another forum and one reply suggested it could be related to the crown ring and pinion's coast side backlash or pinion depth setting and is something to get looked at before it wears to the point of having to replace it rather than just adjust it.

    Thoughts?

    Thanks.
     
  2. rayzazoo

    rayzazoo DRIVESRT.COM Gold Supporting Member

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    Take the write up you have here to the dealership. Get one of the service managers to do a ride along with you.

    Sounds like a rear end warranty replacement, or at a minimum, new rear gear oil.
     
    Last edited: Jul 6, 2016
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  3. rayzazoo

    rayzazoo DRIVESRT.COM Gold Supporting Member

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    srtjay check out the thread linked below and see if your 392 is applicable.

    New TSB 6/24/16: Inspecting and replacing the propeller shaft due to a whining noise at high speeds
     
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  4. srtjay

    srtjay Active Hellcat Member

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    Thank you for the link, my build date is in the timeframe listed for that TSB so I'll print and bring that with me as well. My sound is on deceleration coasting and much lower tone than the video you linked in that thread, but maybe this sound comes from the same source.
     
    Last edited: Jul 8, 2016
  5. srtjay

    srtjay Active Hellcat Member

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    So they said they would need the car for the entire day in order to diagnose the issue. I said I wouldn't mind waiting for a couple hours while they diagnosed but not all day. I also offered to do a drive with the tech to point out the sound so he could diagnose but the adviser insisted they'd need it for the whole day. No thanks. As much as I was hoping to get ahead of a potential issue, it seems I'll just have to wait 'til it gets worse or something actually breaks so they don't have to spend all day with the car just trying to diagnose it.
     
  6. rayzazoo

    rayzazoo DRIVESRT.COM Gold Supporting Member

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    I got the same thing from the local service manager here. After talking with him, it was really that they had 40 cars requiring service in their department so he said to come back later next week.
     

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