Did you shop check your vehicle for failure codes in TCM.Your transfer case is computer controlled & will leave an error message when an input is selected & not carried out.This is where the diagnosis should begin.Are you referring to the pin /shaft on the transfer case or the front axle assembly?
Ok,you do realize you must take apert the front axle assembly.Good luck
Front Drive Axle Inner Shaft and Inner Shaft Housing Replacement
Disconnect the wheel drive shaft from the inner axle shaft.
Important: Keep the open end of the inner axle shaft housing up.
Clamp only on the mounting flange.
Carefully tap the inner axle shaft into place with a soft-faced mallet.
Ensure the tabs on the thrust washer (5) align with the slot in the inner axle shaft housing (4).
Drive the clutch gear into place with a plastic hammer.
Tighten Tighten the inner axle shaft housing bolts to 40 N·m (30 lb ft).
Tighten Tighten the inner axle shaft housing nuts to 100 N·m (75 lb ft).
Tighten Tighten the wheel drive shaft inboard flange to inner axle shaft bolts to 79 N·m (58 lb ft).