Back-story:
I bought our 2003 2.5L X-type about 9 months ago. Although stunning cosmetically, the seller (a friend) made me aware of some functional problems - among them front and rear suspension, and tires. New Bilstein comfort struts and shocks plus various and sundry related fitments, and, a set of Yokohama Avid Ascend Grand-Tourings has this sweetie riding and handling like a dream. The downside is that the now-eliminated roaring of the old cupped tires has made another roar/low whine/hum very much more noticeable. The suspension technician says that he suspects that the cause of the noise is either the carrier bearing, or a rear wheel bearing, or, possibly both.

The Dumb Question:
While cruising along at 40 MPH I have shifted the auto tranny from drive into neutral and coasted for a few seconds. The noise does not diminish nor change in any way.
Does this mean that I may scratch the carrier bearing off the list of possible noise sources? Or, are the driveshafts/bearings still spinning although not under power?

Did I make things as clear as mud?

Any responses will be appreciated!






.

 

Does it hum a song or does it just go hmmmm...?

 

Time traveler,
Just to prepare you for worst-case scenario....
I have my 2005 in the dealer's shop right now. It's getting a new transfer case installed due to the low whine and low roar that I originally thought was a wheel bearing. No such luck. Ouch, this is gonna hurt.
The only consolation is that they gave me a new XF Supercharged to use as a loaner for a couple of days. I think they felt sorry for me...I was not expecting such a huge repair bill. I've replaced drive shaft and wheel bearings before so when I heard the noise before I bought the car, I figured it would be fairly painless to fix it.
Good luck, hope your noise is really something less sinister.

Tom

 

When the X400 was introduced it seemed like we lived to fix all sorts of driveline noises.

Here are some old TSBs to read in case these are the causes.

bob gauff

 

Actually it sounds vaguely like "Hit the road, Jack".

 

Time, what I want you to try is getting the car out on a rural highway (so you have a lane to change to) and get the car making the hum. Now, in a controlled manner, make a semi aggressive lane change (enough to cause the body to roll just slightly). Make the lane change back to the original lane. During these lane changes, did the noise go away when you went 1 direction but not the other? If so, the direction that you turn to make the noise go away is the side that the wheel bearing is bad. Then it is just a matter of determining if it is a front or rear bearing. If it is a front bearing, make sure that the shop that installs the bearing puts it in correct (yes, there is a front and back to the bearing). If they install it backwards, you will get an ABS light on the dash.

The other thing that you can try doing is getting the carrier bearing greased (can do it yourself, just need a needle attachment to a grease gun to get the grease inside the bearing). If this causes the noise to go away, then you have some more time, but you may want to start looking at getting the carrier bearing replaced.