On an 01 literally everything will fit somehow. Just make sure you put the dummy stub axle back through the new unit bearing and torque it to 175 foot pounds to keep the bearing from separating and tossing your tire off rather unceremoniously.
Balljoints: the same for any year XJ (iirc) and 93-98 grand cherokees (ZJs)
Knuckles: the same for 92.5-01 XJs and (iirc) 91-92.0 4wd XJs as well (early 90s 2wd XJs had a different one.) I think ZJ parts will cross over here too but not sure. WJ (99-up grand cherokee) will, but you need to use their balljoints and do other mods as well, search
for "WJ swap" using google.
Calipers: same as knuckles, any 92.5-01 should basically have the same ones, ZJ as well I think but not sure.
Rotors: 99.5-01 XJ are all the same, 92.5-99.0 are compatible if you also swap the unit bearing from the same jeep
Unit bearings: 99.5-01 XJ are all the same, 92.5-99.0 are compatible if you also swap the brake rotor from the same jeep (I suggest buying new of the appropriate year instead, or at least swapping both sides from the donor, along with the pads, keeping them matched with the rotor they were with.)
The whole axle housing will swap, actually - any 92.5-99 will bolt right in and you just put your unit bearings and brake hardware on it (if it's a 99.5 donor, you can simply swap your calipers and rotors on, compare the unit bearing center flange height to find out.) Obviously you won't get 4wd, but you'll be one step closer. I ran my MJ with a 4wd axle housing with axles and gears in it for a year before I ended up actually converting it to 4wd and it drove and handled better, though that was mostly because I replaced the front coils and shocks at the same time as I swapped the 4wd housing in so the added unsprung weight wasn't really noticeable.
atriot:
