my experience:
Back when I lived it the wet cold frozen midwest, I occasionally had a little trouble getting the auto hubs to disengage at below 10 degrees.( I think all Raiders / monteros after 84 came with auto hubs).
A guy I worked with had an old Blazer. He said unknown to him, he had one auto hub locked up and the other wasn't. After running around at internet speeds something gave.
Although the auto hubs that come on the Mitsu are of superior quality, I just don't like taking chances. This isn't something you "Have" to do , it's just preferred by most.
I think there is a post under special deals on some brand new ones. I got mine off an old D 50.

dave h.
'89 Raider V6 5spd;Aisin Hubs;; Gen2 LS: frt. brakes, rear coils;U.C.arms;R.trailing arms;idler arm; rear LSD axle w.disc brakes ;2 battery system for Dog's fan; relocated ECU; custom bumpers;J.Baker receiver;Conferr roofrack; t-bar crank.