You felt it binding when turning, so it still is working.
Driving around in 4wd is bad for the system because of that binding, which happens both when turning, and if the front tires are a slightly different diameter than the rears.
There are two ways for that binding to "release"
a) one of the tires skids a bit.
b) something fails catastrophically.
You are still on tires skidding a bit.
So, your tires have worn a bit, and there's a bit more wear on the transfer case and the front diff, but your 4wd system is still working fine.
2004 GMC Sierra 3500 C&C, added 4WD, 6.0L gas, Extended Cab, SLE, Transgo 4L80e-HD2 kit installed
Whee! Dually Club Member #1109