01 suburban 4x4 issues

[psbuilder]

My 01 suburban's 4 wheel drive isn't working.90000 miles on it.The transfer case servo motor is turning,the front axle actuator is extending and retracting,I can not turn the front drive shaft when the dash push button says its in 4 HI.Do i have an issue with the clutch plates in the front diff?Any help here would be great.

 

[Magnum44]

Just curious but did you remove the T-case actuator? Possibly it's in the gear set, shift fork etc. Unfortunately these actuators are cheaply made (IMO). The front axle actuator has a plastic planetary gearset that lines up forward and reversing contacts for engauging and disengauging the motor. Doesn't seem very heavy duty to me. Haven't had a T-case motor apart. Anyway, if you remove it you can probably check the actual output side to the T-case to see if it is moving as the motor turns.