I have 97 GMC Sierra was wondering if the front drive shaft is always supposed to turn in 2wd, it has the 4x4 in the floor and i just replaced the 4x4 actulator and now it locks in 4x4. I dont wanna wear something out if not supposed to turn, cause when i jack up on wheel and spun it over the front drive was turning? if anyone could help me I sure would appreciate it thanks