4WD Problem Continues

I've basically eliminated the 4WD actuator from being the problem, it engages, the plunger extends, however nothing locks in in the front axle. I jacked the truck up, put it in 4HI (electronic T-case), pushed a rachet handle in where the plunger would go and pushed the plate in with just as much force if not more, and the front wheels free spin. Something isn't locking in.

Anyone ahve any ideas what I can check next? Winter is almost here and 2WD and snow doesn't mix!!!

Thanks!

man go to the dealer and they will tell you wrong you will pay 90$ for it and then you can fixit your self thats what i did whit my its was the motor actuator yours maybe the front actuator its like 60$ good luke

Wow ... thanks. Anyone that actually read my post? lol

With the fronts off the ground and in 4 hi or 4 low can you turn the front drive shaft? If you can it's probably a t-case problem. Otherwise you'll just have to get into the front end and see what's not working.

Well I have it all solved. Upon removing the actuator and trying to engage the front axle myself, I found that something was jammed and I couldn't get the piece to slide over. I'm no where near a mechanic so I wasn't going to attempt to rip the front axle apart. I took it to get it looked at and after ripping the front axle apart they found that the "input shaft" (explained to be like a clutch assembly that slides in to lock everything together) was broken. There was a piece broken and it was causing everything to jam up. I asked how this could happen since I really only use my 4WD in the winter, and he said in the 20 years he's been working on trucks he's never seen it and the tech working on my truck was trained at the GM factory and worked there and on contract for them for 16 years and has never seen something like that before. I asked what would cause it and he said it was probably something as simple as a Monday part and a Friday part when it was assembled and something never lined totally but enough to not be noticed and after 70k miles it just had enough stress and broke loose. All in all, the part is $480 (add $40 to overnight it), they need to replace the bearing in there cause he's sure it's going to break removing it, a few shim pieces, with labor and other parts, new axle seal blah blah I'm looking at $1,290.00
Just what I wanted before Xmas. There's my luck for ya!

Thanks for everyones input into this, I'm just happy the problem is finally being solved!