4x4 not working help!

[acbrownie15]

99 3.0 automatic acts like it's engaging but no 4x4 if it's not engaged I can spin front drive shaft if it is engaged I can't spin it is it the
transfercase?

 

[kamps989]

I do believe that you should not be able to spin the front drive shaft while it is engaged as it is now connected to the rest of the drive-train. If there is no flashing of the 4x4 lights on the dash my money would be on one of the vacuum hubs failing. Extremely common problem and Ford stopped using them mid 2000 model year. I replaced mine with manual hubs instead of new vacuum hubs, however if you dig on the site there is a way to convert the vacuums to a manual in kind of a sloppy way.

 

[kamps989]

These are the hubs I bought
http://www.jamesoaksenterprises.com/index.php?main_page=product_info&cPath=96_108&products_id=273

Heres the article that will allow you to manually lock them and you can always leave them engaged causing them to act like mid 2000 and newer systems
http://www.therangerstation.com/Magazine/Apr04/offroad.htm

And this article should help you troubleshoot
http://www.therangerstation.com/tech_library/troubleshoot-fix_pvh_hubs.shtml

I cant emphasize how crappy the vacuum hubs are (and the T-case motor for that matter)