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Author Topic: Unexplained high pitched whine Explained  (Read 2026 times)

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Offline 1oldracer

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Unexplained high pitched whine Explained
« on: April 08, 2013, 01:20:00 PM »
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!!            
If its not broke, work on it till it is

Offline garage gnome

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Re: Unexplained high pitched whine Explained
« Reply #1 on: April 08, 2013, 02:14:45 PM »
I've had this happen on other vehicles too. Never had it happen to my Willys though. Thanks for taking the time to post this up! I'm sure someone in the future will benefit from it.
Nate in Western MA 1953 3A #3268, The Jalopy, '47 2A Wheelin' rig, '49 3A, #37071, unmolested, bone stock named Ted

Offline Gunslinger

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Re: Unexplained high pitched whine Explained
« Reply #2 on: April 08, 2013, 05:46:32 PM »
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

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Climbs trees, hides in the long grass, hangs out with wet dogs...

Offline duffer

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Re: Unexplained high pitched whine Explained
« Reply #3 on: April 09, 2013, 01:30:58 PM »
1) Well, heck, just means if it had fallen off the jack stands with 40 mph static speed going, you may have found that sooner. ;D

or 2)  Need a louder muffler
48 2A, 49 3A, 51 Wagon, 55 3B, 57 FC 150, 57 Wagon, 60 FC 170, 68 CJ 5, 2012 JKUR

John, Bozeman, MT

Offline johnrb3b

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Re: Unexplained high pitched whine Explained
« Reply #4 on: April 10, 2013, 10:59:39 AM »
Quote
or 2) �Need a louder muffler
Yeah, I like that.  ;D
1946 2A - - - 1949 me - older than most of my Jeeps
1954 3B - - - 1957 Wagon - - - 2010 4-door JK
past Jeeps ---> '54 3B - no tub --- '59 3B - no engine
past addiction - VW ---> '69 bus --- '70 camper

Offline Macgraham

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Re: Unexplained high pitched whine Explained
« Reply #5 on: April 11, 2013, 09:32:51 AM »
I had one of these too. Turns out it was my wife when she saw how much I was spending on the Jeep. Thought I got it handled but it comes back once in a while!!! Think maybe it's fixed now cause I let her drive it the other day. She was pleased.