Oh yeah I forgot to post the rest of it. (Wife was bugging me about something
) On A.D.D. cars, if you don't drive in 4wd often, sometimes the hubs will not lube itself and it will not engage. When you switch the little vaccuum hoses underneath the front diff, you are manually engaging 4wd... of course you would want to switch the hoses back after you've driving in 4wd for a while. That did the trick for me but I'm not sure if it's different for automatic 4runners.