That shaft is tapered so when the nut is tightened and torqued to spec it stays in place for the life of the gearbox. When removing them most make a relief cut with an angle grinder. They almost never come off with just puller.
89 2.5 TBI, 4" RC lift, 1" Booms, SYE, Adams Driveshafts front and rear, Ford 8.8 with 4:88s, BFG 33X12.50X15, and a ton of other stuff.
AF Jeep Club Tail Number 184