Not mine, but my son's XJ....
(well, mine by title)...
Ditched the fan clutch and its associated stock fan in favor for a flex fan and aluminum coupling/spacer to go in place of the existing fan clutch. Despite measuring the old fan and so on, we finally zeroed in on the coupler size...
97 4.0, auto. 4x4 FYI...
15" CCW rotation, with a 2.25" fan spacer seems to be the ticket.
The existing fan clutch passed the spin test, but he couldn't sit in traffic with the AC on without the jeep overheating. Seems that this solved the problem. I should note that we replaced the head 5 years ago, have tested for combustion gasses in the coolant. Coolant/hoses/belts/WP are all within 1 year of brand new and always LT warranty parts from a reputable manufacturer when available. Coolant SG is within spec, pressure tested, etc. My son is a pro wrench for the local Jeep Dealership.
I had a similar issue with my 05 Liberty overheating last year, solved it the same way. Apparently I had a couple bad fan clutches in a row. I can no longer trust them, as they cost me 3k in engine work (pull the heads, machine and replace) so my Jeeps are all going back to old school flex fans.