Our jaguar x type has a funny whirring noise coming from the rear o/s wheel when travelling on the motorway. The brakes dont seem to be binding. Is it likely to be a dry wheel bearing or is there a common fault with the rear diferential/ halfshafts? its only done about 35k.

seized brakes or brake parts dislodged and binding. the fact that you put on the brakes and it stops are a good clue

Hi, from your description it sounds like you have a wheel bearing problem in the rear of the car. It is common to have one or both wheel bearings fail causing a whirring type noise like the one you are hearing.
You can get the parts in the USA on this LINK......

The following describes the entire rear suspension of which if any parts are worn can cause a noise:

Removal & Installation

1. Before servicing the vehicle, refer to the Precautions Section.
2. Remove the rear wheels.
3. Using a suitable jack, support the rear lower arm.
4. Remove or disconnect the following:
   
   Rear wheels Stabilizer bar link Rear lower arm Jack Lower arm from subframe Spring Isolator
   
   

   Fig. Rear suspension assembly-S-Type
   
   

To install:

1. Install or connect the following:
   
   Isolator Spring Lower arm: Tighten bolt to 85 ft. lbs. (115 Nm). Stabilizer bar link: Tighten bolt to 26 ft. lbs. (35 Nm). Rear wheels
   
2. Check rear wheel alignment and adjust as necessary.

For all except the X-Type, the rear coil spring is serviced with the strut assembly.

Have the rear brakes inspected. These are real easy to change if they need to be. You need to look under the car just outside the differential. This is an inboard brake system so the wheels don't need to be removed.

if you have abs the electic noise you hear is most likely coming from the abs modulator. as for the rear brakes intermittently locking up, the most common problem is overadjusted rear brake shoes, under adjusted rear brake shoes, or excessive brake dust inside the drums.

Jack it up, remove the hub and see if your brakes need adjustment or replacement. The noise coming from the area may be a squeeling dragging or steel on steel sound. This noise is a caution to replace them. Good Luck.

a wining noise at motorway speed could be the early signs of your transfer box failing, might be worth getting it checked

Not sure if this is this answer, but I had a problem with a noise under the front end once....turned out to be the cowling under the front bumper....it was broken and it took a high speed to force it down enough to hit the road.

Good luck!!

Check under the driver side fuse box which below left of the steering wheel if there is any dampness then it s screwing the ecu,this could be due to a seal leak in the window or holes near the axle.ALso the transmission needs fluid to be change as most jag trans fluid need replacing before 75k, clearing the codes will clear the engine light which also improve the cars shifting.

it does sound like wheel bearing a cv joint dont make noise and then stop but you can jack the car up and in neutral try to shake the tire from side to side.to see if you have any play then turn the wheel by hand try to feel for roughness in bearing. let me know what you find. Phil.