[1969 GMC]

OK now that I got your attention, I need a little bit of help. When I think my t-case shifter lever is in 2Hi, it can be moved toward the dash a bit (1/2") and it clicks, like there is the gear. But if you let go of the lever, it pops out back to where it was. My question is, is there something wrong with my t-case? I can't check to see if my front driveshaft is turning. When I think I am in 2Hi, am I in 2Hi, or is it 4Hi? I know it's not neutral because I have been driving it like this for about 3 months now. It just seems like there isn't really a separation of 2 and 4Hi, and I'd like to be in 2Hi on the roads to save on gas. Or am I just dumb? lol Some input would be appreciated, thanks