I have a wah-wah-wah noise coming from an undefined area of the car, which increases with speed. It seems to start at about 40 MPH and the period of the wah-wah-wah's increases with increasing velocity. Car is a 2009 XF SC with 60K miles. What are my options if it is the diff?

TIA

- Tim

 

The diff will usually howl or give off a grinding sound. Your problem sounds like tires.

 

Wheel bearing. Just barely had mine replaced and it sounded just like yours. If it's really bad, you can jack the car up and try to shake the wheel on the car. The culprit will be the one that moves a little bit.

 

Thanks gents, I will jack it up and see if I have any play in the wheel bearings. Any how-to DIY on the wheel bearings? Tires are also due for replacement in the next few months....

 

I agree that you should make sure it is not as tire. From your description it seems to me it might be a tire ply separation happening which can be dangerous if it progresses.

 

RrrrRrrrRrrr, crunch, bang, clang, thump, thump, screeeeeeech.

 

Is the screeeeech the diff, or your reaction when the dealer tells you the cost...

 

Tires locking up, coming to stop.

Then

The dealers quote.


On a side note, I had a transfer case seize on my 1992 US spec Mitsubishi Galant VR4 at 55mph. A loud bang and all four tires locked up. It was the fastest 55 to 0 I have ever experienced. It was brutal.