Just recently purchased a 1998 XJ8 at 94,500 miles and wondering if I should address the transmission in any way as regards a flush or adding trans fluid. There’s no indication of an issue but wondering if I should be preemptive to avoid any future issues.

 

Your over due for a fluid change? I would not do a flush but it's up to you. If you plan to keep the car get it done before you get more miles on it.
It's just good maintenance.
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keeping fluid may prolong agony but mechanics are meant to run on adequate quality oil and after all those miles and years oil is all but wasted.
as for me, if you are going to keep it, and can throw some money at it, have at least valve block fixed or get one refurbished, those units are made of too soft alloy and end up worn prematurely leaking pressure, cracking and at this stage breaking other stuff.
if you wanna do it yourself there are excellent video on yt about doing valve block job, while at this have both pressure and torque converter valves replaced with sonnax or/and transgo stuff
this is somewhat medium pita job but you don't have to pull the box and unless something else is damaged it should keep you fixed for long

 

ZF published a 5HP24 repair manual and the recommendation for fluid change was EVERY 10 YEARS.

 

Drain and fill new fluid that's enough I did flush and the transmission died and to the scrap yard

 

i imagine those 10 years are a compromise between "we broke your sealed for life box" and "you should do it as frequently as any other transmission"
after see how they messed this particular model and tried to cover the tracks later i would rather take their advice with large spoon of salt and lower it to every 5-7, in any case RB is at lest two changes behind unless previous owner did it

 

Jaguar claimed the box was 'sealed for life', ZF DID NOT!!!!!!!!!!

 

if that is true, than they both are implicated in producing and putting on the market quite a chunk of garbage, doesn't really matter who recommended what, final result is quite abysmal.
rr & bmw owners be my witness

 

I was told somewhere that 6years/60k miles the same as the supercharger oil was a good time to change the transmission fluid.
I think it's the same interval for the diff oil too, so easy to remember.