My Jimmy makes a vibrating noise over 40 mph and a growl

well, assuming it's not a clunk or tick, jsut a vibrating noise and rumble or growl I'd say either your tire or tires need to be balanced, or more likely it's a bad wheel bearing(s).

I would say a bad wheel bearing as well and even possibly low fluid in the rear end gears.

Yes it is most likely a wheel bearing. FYI I own a repair shop and you do not want to use a inexpensive bearing. Go to napa and get the good one. I promise if you do not use the good one, you will be replacing it again. It should take 1 hour to change and the bearing is about $250.00

I replaced the wheel bearing didn't help , then replaced the front axle shaft on the side that sounded the worst still no good