Stuck in 4wd or 4wd not working at all??

[Tiger07]

So my 5R55E automatic transmission went this summer and I had it rebuilt and put back in (i took it out and put it back in myself). Shifts a little rough into the first two gears but everything else is good EXCEPT I cant tell if my truck is in 4wd or not. I know the electrical components are working because when i turn the switch from 2wd to 4wd High, it makes the indicator click sound and the light comes on and everything. The thing I'm worried about is when im driving and switch to 4wd it doesnt seem to feel any different. I really want to fix this before winter comes because im not looking forward to having to drive more carefully on the slippery roads or not driving the highway at all in fear haha. Is there any way i can tell if it's stuck in 4wd or just not going into it at all or what? Any help is greatly appreciated.

 

[adsm08]

While this is generally not advised, it is the quickest, dirtiest test I know to check 4x4 operation.

Go to an empty parking lot. Drive slowly in a tight circle. Stop and shift into 4wd. Continue in the circle. If it shifted, you should know pretty quick.

Even on the electronic 4x4 units the light runs off a switch in the case that is physically activated by the engagement of the forward output. So if the light is working as commanded, odds are very good that the system is working.

 

[mitch4x4]

I 2nd that.

Also these motors are known to go at random. Mine went on me in a snow storm...at least I was in 4wheel drive when it decided to go.