It's possible, the biggest give-away is if you have a lot of front wheelspin on hard acceleration.
I'd go test it on gravel or a slightly muddy surface. If it doesn't haul and sits there for a second spinning the fronts you'll know. If it is the center diff, now would be the time upgrade, OEM broken comes out, upgraded stuff goes back in. After only 7-8 years I don't see how it could be worn out already, but if it's broken, it's broken.