My KJ has had a pretty easy life, lol. It's all stock. A/T tires but not oversized. Not much towing. I commuted long-distance on the freeway daily for 12 years so not much stress and strain except for driving in the extreme summer heat and dust here.
Mine made it to 195,500 before it grenaded ! Not cheap to fix but as "R" says, they aren't worth much but it sure is fun driving one ! I've seen some people in traffic give me good look as it's pretty nimble and fairly quick in the 40 to 65 mph range (on flat ground)> All mine transmission did was go into limp mode, stuck in high gear. After 5-10 min cool off it would work for a couple of miles and repeat. Hard to start out in top gear. Sometimes it would shift manually and that is how I made it to the shop. Now it is smooth as any transmission I've ever owned. Usually can't feel it shift.