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.