When I first got my 4Runner, I had to lock/unlock the hubs with pliers because it was too difficult to turn by hand. I figured a hub rebuild was in order. There are several excellent write ups on the internet for Toyota Aisin hubs. Here are some links:
After following procedures from the above links, my hub dial now turns freely with ease. When I disassembled my hubs, they were bone dry and there was lots of surface rust. I cleaned everything up and applied a light coat of grease. Here is what they looked like
Nice rust on the inside which was making the dial hard to turn
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