Rear diff

[discojools]

Does a dodgy rear diff give a high pitched whine or a low drone? Is it on throttle or on the overrun or both? Thought I heard low drone today.

[woko]

Mine was a low drone. Didn't make much of a difference between on or off power. The front pinion bearing is usually the culprit

[Badger51]

Does a dodgy rear diff give a high pitched whine or a low drone? Is it on throttle or on the overrun or both? Thought I heard low drone today.

Diff drone & tyre drone can sound identical! How much tread do you have on the rear tyres? The only way to be certain if the noise is diff bearing is to find someone with a set of chassis ears. That will give you the answer almost immediately.

Good luck with it,

Nick

[PhilipA]

Usually a pinion bearing will make more noise on overrun as the crown wheel and pinion move out of alignment.

When I had one go in my BMW M3 , it also made a "Wonka Wonka" noise when just crawling along.
Unsurprisingly a carrier bearing will sound like a wheel bearing with a constant drone.
Regards Philip A

[FisherX]

I thought the diff bearing issue was only a problem in the first couple of years. Looks like yours is a 2013 so I'd be looking at your tyres.

I had some real nasty tyre noise in ours when we first bought the car. It had Goodyear Wranglers on it then and even though the tyres had plenty of life left in them the outer tread blocks had worn unevenly.

Run you hand around the tyres tread and see if you can feel any uneven wear. Especially on the outer edges.

[discojools]

Unfortunately not the tyres. It sounds like it’s the carrier bearings as it’s a constant low drone whether on or off throttle. Confirmed by my local Indy.