Steve.
I assume this is down to a simple worn near side track rod ball joint end. This appears to be C2C20177. An initial internet trawl shows Berkshire Jaguar as stocking the part at £17.80 plus VAT.
http://www.berkshirejagcomponents.co.uk ... Parts.html
To replace the track rod end, some heat may need to be applied to the lock nut and inboard part of the track rod end together with flooding with WD40 or similar releasing fluid. The nut, track rod and rack rod tend to corrode together. Heating helps the release process. Only slacken the nut about one quarter of a turn so that you do not loose the toe angle setting. Remove the nut on the vertical hub carrier and drop the track rod ball joint down. a clump with a hammer after the nut has been removed, usually parts the two components. Screw off the old worn drop arm counting the number of turns before it comes off the end of the rack rod. Clean up threads with a wire brush and apply a little copper grease. Fit the new track rod end and tighten the lock nut. Engage the ball joint on the track rod into the vertical hub carrier and torque to correct figure.
I would also check the off side track rod end for wear. If I were doing the job, I would replace both track rod ends together and place the parts receipt in the car maintenance file.
If the wear is in the steering rack rod end, these parts are available.
Wheel bearing wear is quite common from about 80k miles and manifests itself as a speed related "wirring" sound. OE quality bearings can be found from around £80. Fitting usually requires the use of a bench press. The old steel bearing case corrodes to the ali vertical leg. The corrosion by-product "welds" the two component parts together and separation is almost impossible without a press. I`ve used pressures of up to six tons to get these two components apart. They separate with a hell of a bang! Unless you have a press, this job is best left to a garage.
Mike K