Whine/hum from rear.

[tommyd]

hi. So after 9000 miles ny dark horse manual started to nake a high pitched whine/hum sound from the rear . It only makes this sound when I excelerate getting louder as I push down on the throttle. It doesn't do it iif I rev it in neutral. My local food dealer says it's normal
. I know it's not
Could I be the pinion bearings? Thanks

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[Cz_Ziemniak]

I'd get that checked out at an indi shop.

Rear diff's really shouldn't whine. Could be lash, could be bearings, could be low on fluid. Check it regardless. There was this whole thing awhile back where people would receive their S650 and the fluids would all be low, either for transportation, or whatever other reason.

 

[Skye]

Have you taken the car on a test drive with a mechanic? Have you recorded the sound?

You have a DH. Are you able to monitor the temperature of the diff on-screen? If so, how is that?

I can think of a few things:

- Inspect the rear tires for any unusual wear

- Check the oil level in the diff and for any leaks

- With the rear of the car off the ground and the car in neutral, the wheels and rest of the drivetrain could be inspected for anything loose, making noise when turned, etc

- Afterwards, the car could be started, put in gear and slowly accelerated

If you can accomplish yourself, great. If not, I'd expect the dealer to charge $150 diagnostic fee. I'd like to think the fee would be waived if problems covered under warranty are found.

If you have the checks performed at a local shop, they'd probably charge an hour of labor.

 

[Yamazuki]

Oh man, mine groans.....and growls......and groans.....and growls.

Loudly.

Every time I start backing up. It's pretty much done that ever since I put the solid alumininininum (or steel, whatever they were...) bushing lockouts on the 'pun-kin'.

 

[steveo1960]

I have a similar problem only the whine is coming from the front of the car.
Oddly it only happens when the wifey is with me so the fix is simple.

<Rimshot> !

Staying on topic, check out this site for general diagnosis/symptoms.

<https://differentials.com/diagnosing-differential-problems/>

 

[tommyd]

Thanks for the feedback. The diff,axle hub/wheels bearings and fluids were all checked. The service managers drove the car and acknowledged the sound. They couldn't replicate the sound on the lift, so they gave up and told me it's normal.

 

[Cz_Ziemniak]

Thanks for the feedback. The diff,axle hub/wheels bearings and fluids were all checked. The service managers drove the car and acknowledged the sound. They couldn't replicate the sound on the lift, so they gave up and told me it's normal.

If its a Ford dealer, then thats not a surprise.

Get a second opinion at an independent shop.

 

[Sofa King]

I say wheel bearing... Recently I had another car with whine/humming noise in the rear... dealer wanted to replace the driveline ($3000), but I knew that was just them throwing maximum dollars at it. A little more diagnosis on my own narrowed it down to the wheel bearing and the noise is all gone after replacing it.

 

[MidwayJ]

When I had a whine from the rear in my S550 it turned out there were metal shavings in the diff fluid. But it sounds like you already had that checked.

 

[tommyd]

So they say. Double checking it with another dealer

 

[tommyd]

So another dealership diagnosed the hum due to a bad axle bearing. Probably came that way from the factory. Hopefully they resolve this issue

 

[Sofa King]

So another dealership diagnosed the hum due to a bad axle bearing. Probably came that way from the factory. Hopefully they resolve this issue

HA, I CALLED IT!
Hopefully they get you taken care of quickly!

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