Ford Repair: Is my 4 Wheel Drive working?, giving me a reason, noticable change

Question
Hello Mr. Bond,

First of all, thanks for giving me a reason to say those three words.  :)

Second - I have a 98 F150 XLT 4x4 -
4.6L v8
Manual Trans
76k miles
4wd is enaged via the gear shifter on the floor - not electronic/push button

I purchased this truck in the summer of 03. I bring this up because I was successful in engaging the 4wd when I took it on a test drive, but that because it was summer / only a test drive I was not able to "really test" the 4wd.

My question is this... how do I know that my 4 wheel drive is working, and what should I expect in response / traction from this vehicle?

When I engage the 4 wheel drive (high) James, the 4x4 light comes on near the tachometer, and I feel a 'slight" change in the way the vehicle drives. Beyond that, there is no increase in traction - when I am driving in snow, the back tires (or rear right-only) continue to spin, and the front tires do not seem to grab at all.

When I engage the 4 wheel drive (low), the 4x4 LOW light comes on near the tachometer, and there is a 'noticable' change: The change to lower gears is apparent (along with the "clunk" sound), but again, it does not appear that the front tires enage at all.

So - does it sound to you like the 4wd is working? Am I expecting my truck to have super-powers, and actually have a completely working vehicle? Is there some truth to what my mechanics have mentioned, which is the "actuator" may not be working?

I truly look forward to your reply, James... now that winter is upon us in Milwaukee, WI, and my 4wd feels like 1 and 1/2 wheel drive!

Thanks in advance,
Andrew

Answer
Sounds to me like the actuator isnt working like it should. If you were in deep, snow up to the tires, and the 4 wheel was engaged, it would pull you right out. You can almost feel the 4 wheel drive working. Your mechanic is right... Thanks,, and stay warm,,, -37 below here,,