Front end vibration
 

Hey guys. New to the FJ here. Just picked up an 08 in June of this year. I'm still trying to get to know this thing. I upgraded from an 86 4x4 pickup. Main question I have is that now that we have some snow here, when in 2wd, if I step on it and try spin the rear wheels, the whole front end vibrates as if I'm hammering on the brakes and the ABS is kicking in. Even in 4wd it doesn't seem like I'm getting full on abilities (if that makes sense at all). I know its engaged based off of the way it turns at low speeds and tight turning radius but I just dont know about the vibration thing. Any ideas?