[Short 3/4]

Not sure if your year was still closed knuckle, but if so you actually want to drive it regularly with either the hubs locked and shifted into 2wd or hubs unlocked and shifter in 4wd. That is the only way to keep the upper bearings in the knuckle lubed properly. Also as you found out u-joints that aren’t used (and lubed) regularly don’t age well.
Locking hubs were invented well after modern 4wd systems and for many years were an option, so trucks like mine, which didn’t come with them from the factory drove around all day every day with the hubs “locked”. The opposite of what you did, but with the same result of the front diff and driveshaft constantly spinning.
Hope this all makes sense and helps
Tom