Hi all. My 1992 Mighty Max 4x4 won’t go into four wheel drive. The transfer case is shifting fine. I suspect the automatic locking hubs are failing. I took a peek at the driver’s side hub today. No obvious problems. I’ll check the passenger side tomorrow. The hubs appear to be purely mechanical (no vacuum lines). If I see no obvious problems on the passenger side hub, then I’ll tear down both sides completely, then clean and grease them. Is there anything else to check? It seems like a simple system but it’s my first time digging into it. Outside temperature is around 30F. I don’t think it’s cold enough to be a factor but worth noting. Thanks.