Hi,
I have a 99 GMC jimmy 4x4, 91k miles 4.3 V6, I have had this problem, which didnt start untill the person I bought the truck from took out the Transfer Case Control Module, because it quit working. Anyways the problem is (besides no 4x4) I have a pulsating humming noise in the front end (kinda like a wheel bearing hum, but it pulsates, not constant).
I have checked the wheel bearing by taking ahold of the tire at the 12/6 positions and the 9/3 positions and wiggling the tire, it is tight NO play, I've checked the tires, I even put the spare on the front to see if that took care of the problem, but it didnt. So what else could I check out?
Is there a way that the X-fer case is some how messed up because the Control Module isnt in the vehicle? Or could be transfer case maybe be out of oil?
Any suggestions would be helpful. Thanks