Chevrolet Repair: 4 wheel drive, drive shaft, gmc jimmy

Question
My 2000 GMC Jimmy is in 2 wheel drive The drive shaft out of the front of the transfer case is turning And it is locked in with the rear tires My 4 wheel drive does not work and that's okay With me for now But I am now getting a vibration inside the cab And my I believe my u joints on the front driveshaft are shot can I pull that drive shaft yoke in all out and run it that way or will it leak oil

Answer
GOOD DAY JOHN,,THESE FOUR WHEEL DRIVE BLAZERS CAME TWO WAYS >>> NEW PROCESS GEAR OR GM AUTO LOCK. SO THE WAY THE FRONT DRIVE SHAFT GOES INTO THE TRANSFER CASE WILL DIFFER. ONE WAY THERE WILL BE A FIXED YOKE GOING INTO THE TRANSFER CASE WHICH THE DRIVESHAFT WILL BOLT TO THIS THE SAME WAY THE REAR SHAFT BOLTS THE REAR DIFF.[YOKE]. THIS WOULD BE IN YOUR FAVOR.. THE OTHER WAY IS THE DRVE SHAFT WILL SLIDE INTO THE TRASFER CASE,SO IF YOU REMOVE THE SHAFT FROM THE TRANSFER CASE ON THIS STYLE IT WILL FOR SURE LEAK OIL...BUT MAY I SUGGEST YOU REMOVE THE WIRING HARNESS FROM THE BACK SIDE OF THE TRANSFER CASE MOTOR AND THIS SHOULD TAKE IT OUT OF FOUR WHEEL DRIVE...MORE THEN LIKELY THE SWITCH IS BAD...JUST A GUESS AT THIS POINT..GOOD LUCK TO YOU AND LET ME KNOW HOW THIS GOES...TOM..