How to tell if 4WD engages

[Lost216]

how can I tell if my 4WD is engaging? I have the stock auto hubs, 170K miles, and the last owners were rough on it. Every time i'm stuck, the driver front wheel does nothing. I read something about a guy turning the axleshaft, or something, so I was hoping that someone could tell me what to do. Also, for the longest time whenever I used 4WD there would be a loud clunking noise, but lately it has stopped completly. I'm not worried about that, but I thought it would be worth mentioning. 1991 XLT

 

[Blee1099]

Find a rather large area filled with that nice wet sticky mud and drive into it.. If your stuck and you see your front wheels spinning then you have 4WD and your stuck

Kidding aside, put your truck on jack stands front & rear and shift it into 4WD and see if you see the front wheels engaging.

 

[Lost216]

I was hopng for something a little more technical......
I thought of doing that, but it looks like I need more jack stands. I really dont wanna do this on cinder blocks.