Since the forum has been good to me I will swallow whatever mechanical credibility I have if it will help some poor soul in the future running the search engine trying to find out where a high pitched sound from the front of the Jeep like a bad crank shaft bearing might be coming from.  It was a bad sound.  One of those that says - this is going to be expensive to fix.  I asked for help from more experienced Jeep people and got some really good ideas but, unfortunately, none of them panned out so I set out to apply reason and trial and error to pin it down.  Engine eliminated as source (Whew!!)  Coasting down hill with the engine turned off and it still screeched.  This also happily eliminated the water pump, alternator, and fan belt as possible culprits.  Front differential and axles eliminated.  Coasting down hill, TC in 2 wheel and the lock out hubs locked out (this also eliminated out of phase universal joints).  So it had to be wheel bearings.  Put Grunt up on four jack stands, grabbed the stethoscope, locked in the hubs, pulled out the throttle and ran him up to forty miles an hour right in the shop (trying not to think of the possibility of him falling off the stands and shooting himself through a wall) - NO screech!!  Thinking that it might need the weight of the Jeep on the wheels to make the sound, I pulled the drums and re-adjusted and packed the wheel bearings.  Grunt STILL wailed away going down the road.  I knew it couldn't be the brakes as they seldom touch the drums anyway so this is beginning to not be fun anymore.  This morning I was just back from another screeching run down the hill and a friend pulled up.  I asked him to hop in and see if he could help.  We started blasting down the hill and he put his hand on the dash and said "here's your problem".  It was the wind blowing through a small crack in the rubber windshield gasket - WHAT!! No Way!!  Yep, we put the windshield down and - no screech.  On one hand, I am really relieved, on the other hand I think I will go and have a good cry!!            

I too had a terrible noise in Triple X, worked like crazy to find it, no joy, finally one day I was messing around underneath her and I found a bolt that held the driver seat touching the transmission. hmmmmm.  That can't be good says I, it might crack the casting.  Changed the bolt to a shorter one and went for a drive, quiet as a church mouse...hmmm says I.

Todd

duffer wrote on 04/09/13 at 17:30:58:

Yeah, I like that.