Hello Brian in Florida!
Check to see whether your tranny is in SPORT mode. In Sport mode, the shifts
are much firmer than in NORMAL mode. The switch is just in front of the
J-gate shifter, and if you ARE in sport a green light on the lower LH side
of the instrument panel will tell you so. The firmer shifts do not harm the
tranny, as the more slurred shift is achieved by the ECU retarding the
ignition slightly at the point of change, thus sharply reducing,
momentarily, the engine power, purely for passenger comfort and overall
smoothness. The transmission and driveline are designed to absorb quite
significant power shocks - unless you put a V8 or V12 in front of them, in
which case you need a different transmission altogether!
1993 XJ12 (and formerly 1990 XJ6)