To assure that you can lower and raise the spare tire on your Caravan when you need to, I suggest that every few years you lubricate and exercise the mechanism every few years.
I just bought a 1997 Caravan and tried to lower the spare tire. The lower/raise bolt turned a few turns then began to ratchet; I assumed due to rust. I sprayed “Liquid Wrench” into the space around the bolt. That freed it so that I could lower the tire the full distance.
To lubricate the mechanism, I mixed grease and gasoline to make a thin liquid and poured that into the space around the bolt. Lastly, I cranked the bolt full down and full up a couple of times to spread the grease around.