on my 97 f150 with manual 4x4 but an automatic transmission, my 4x4 wont engage sometimes i pull the lever hear some clunking but the front wheels wont hook up. can anybody help me.

 

Do a search on the "Other Powertrain" section.

I think you'll find the info here on this 4X4 problem.

 

I am no mechanic, however I have experienced the same problem along with two of my friends with F150's and we all replaced the same part and it worked. On the front of the transfer case there is a little electronic module that threads in with a wiring harness on the other end. It sort of resembles a spark plug. I can't remember exactly what it is named but if you take the old one out and take it to a Ford garage they can get one for about 40 bucks.

 

Get a helper to look under the truck when the 4x4 is "engaged". If the front driveshaft is turning, there's nothing wrong with the t-case. You probably have either a bad sensor(the spark plug-esque thing mentioned) to engage the vacuum to the front hubs, or a bad vacuum line somewhere.

If the front driveshaft doesn't turn then there's something busted in the transfer case. Expensive and/or difficult to fix.