My Build 1986 4runner SAS 36s etc
http://board.marlincrawler.com/index.php?topic=22625.0

"Later, I learned that even though I engage 4WD my hubs are not automatically locking? Something about manual locking hubs I think. What's manual mean? I need to read a manual to lock them? lol  So I found these neat autolocking hubs and installed them. Sometimes they dont stay locked while I am backing up, but that's fine because I dont have a backup camera to see where Im going (like our RV) so I just simply dont ever back up"- BigMike