Although I have already expressed one problem with my XJS V12 concerning a nasty tendancy to 'dart around' whilst braking (I am still looking into that one) I have also noticed yesterday that after a few miles the steering seems to tighten-up. That is to say that once warm I have to 'undo' the wheel to straighten up as the steering wheel will not self centre. It is not constant - just certain places in the lock when I have to make quite an effort to turn the wheel both into and out of a corner. Not pleasant - especially when treading-on a bit!! It's almost like lack of fluid although that is not the case.
You'll know if the fluid is too low - the pump will make a loud noise like a cat being neutered without anasthetic! It's not easy to overlook!
Sounds like the u/j on the steering column to me - it's pretty close to the exhaust downpipe so the heat may make it sieze. May be worth trying a squirt of WD40 or something before going to the trouble of taking it all apart?
XJS FORUM COORDINATOR
1996 XJS Celebration Conv. (shown on the JEC stand at NEC Nov 2015)
2001 XKR Convertible
1989 XJ-S V12 Coupe. 2006 XJ TDVi Sovereign. 1995 XJ6 3.2. 2013 XF 2.2d. 2009 X Type 2.0d Sovereign estate