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After a relatively mild trip in/around Moab the Jeep started making a noise like the mild roar of tire tread. Didn’t think too much about it but it started getting worse and several hundred miles later it was obvious the noise was not tires. Jacked up the rear end and slapped jack stands under the axels. Noise was coming from the rear diff and was almost certainly in the pinion area. Took it to a mechanic I trust because I didn’t have time to work on it. He agreed it sounded and felt (because of the heat) that it was probably the pinion bearings. Took it home around 25 miles and the noise was getting louder. Parked it and ordered new pinion bearings, races, nut, seal etc. Got all of it together and headed back to the mechanic. By now the noise is LOUD. Didn’t think I would make it. Mechanic just called me and said we were right front pinion bearing was shot and several shims were eaten up. He replaced both bearings and set it all back to specs (they were all correct and tooth pattern correct before he took it apart) However on the test drive the noise is louder than before. He jacked it back up but can’t pin point the source, other than to say it is coming from the rear axle area. TC and Tranny are quite. The wheel bearings were good and the locker engages. Axle shafts are straight. The only thing left is the locker itself. Anyone had this kind of experience with the tru-lok? Noise is most pronounced at neutral meaning not at coast but not under load.

Your thoughts?

:? :?
 

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I have a similar noise in my front axle, I think its the used gear set I put in. Just a little noisy at neutral on the coast side of the gears.
 

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Discussion Starter #3
Eric, Gears were new. tooth pattern is spot on as is the backlash and pinion prepload :?
 

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Put it back on jack stands and in 6th gear with tires off noise is barley audible. Slight load with park brake causes noise to come back with a vengeance. My guess is that piece of crap DC/Fugi locker has given up. Can't tow it to Oregon for annual salmon fishing trip but just as soon as I get back and ARB is going in there! :D
Will let you know if he problem is solved!
 

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Stinger said:
Put it back on jack stands and in 6th gear with tires off noise is barley audible. Slight load with park brake causes noise to come back with a vengeance. My guess is that piece of crap DC/Fugi locker has given up. Can't tow it to Oregon for annual salmon fishing trip but just as soon as I get back and ARB is going in there! :D
Will let you know if he problem is solved!
Why not at least take the locker apart and see if there is something wrong inside it before dropping the $7-900 plus what ever it costs to add an arb pump to move the 90 psi those bad boys need?
 

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Discussion Starter #6
'Cause now I don't trust it! I know there is something wrong inside it that locker.

When I spoke to Dave at Northridge the quote was "I am suprised it lasted this long."

Not to be nasty because I do appreciate your comment, but when factory gives up, factory does NOT go back in!
:-x
 

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44K on the meter and probably another 40k being flat towed.
 

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Stinger said:
.........Not to be nasty because I do appreciate your comment, but when factory gives up, factory does NOT go back in!
:-x
He is not nasty at all! Has just had about 50 bad hands dealt to him in a row. I have similar luck, just not related to all of the same things. If, it failed from anything but, stupidity then, built it better.
 

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Discussion Starter #11
CRAP, CRAP, CRAP, CRAP, CRAP, CRAP, CRAP! :cry: :cry: :cry:

JeepnBlake shamed me into taken the locker apart. :wink:


---getting the damn carrier bearings off is real fun :-x ---
There is nothing obviously wrong inside the locker. It is also obvious why this locker is so weak.
Before I tore it apart I started over with diagnostics. On jack stands run in 6th gear: loud noise coming from diff and hear it very well at each rear wheel. Took tires off and noise was remarkable lessened.
Slight application of parking brake noise was right back.
Pulled both rear axles and ran it again noise was almost absent. So it must need a load on the drive train to make it sound off.
Took the carrier out and ran it with just the pinion in--no noise duh!

Demeral tooled the carrier bearings off with the help of a hammer and chisel! Using the impact wrench pulled the locker apart ---Be real sure you remember EXACTLY where everything goes and in what direction. :oops:

Nothing! No extreme wear patterns. No chipped teeth, No burned gear edges---nothing! :-x

Slammed on two new carrier bearings on and will shove this SOB back into the case tomorrow and see what happens.

No load= no noise or very much reduced. Load the drive train and you can hear the rig coming three blocks away. Pinion pre load is 25 in lbs with new bearings. Backlash is .07 and tooth pattern is centered. Noise is loudest at the neutral piont: just coming off accel or decel but can be heard under either condition.

Anybody had anything like this before? :?
 

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Is it kind of a high pitched whine that comes in, slowly building up in intensity then slowly fading away? Probably highest at around 40-45mph then fading out as you get up to that and then away from those speeds?

Best of Luck,

Mike
 

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Discussion Starter #14
Mike
This noise is almost like a low pitched vibration--almost but not quite. :? Comes in at about 32 mph and gets louder. Until about 50 the is constant at any higher speed.
 

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Did you install Yukon Gears??
Had the same issue, drove me crazy, spend a lot of money on driveshafts, poly bushings, adjustable control arms, straightening axle tubes, different brandsand viscosity of oil, let a really good axleshop rebuild the axle. Nothing helped, noise and vibes are still there. Bought a new Ring and pinion of a different brand, but did not install it yet.
There is a tread (Diff Growl) of DirtyMoney, he had the same problems, maybe he has experience figures with his new gears.
Within a few weeks i will install the new gears, an will post a update
 

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Discussion Starter #16
Thom,
For the life of me I can't remember the breed of gears. They were one of the special deals that Northridge offered. However the 4:88s have been in there quite a while and this is a new noise. Wonder if just maybe I did stress the gears sometime. Didn't do a run out check on the ring gear but guess that would be a good indicator.
 

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In the original message, the description "several shims were eaten up" makes me suspicious. If the shims got ground between the gears, then the gearset was basicly taken out by the pinion failure. It may never mesh properly again.

The gearset contact area should be shiny like a mirror, no visible scouring or wipe marks. If it's not, the gears were ruined by metal in the lube.
 

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Discussion Starter #18
The shims were still on the pinion but burned and torn. No pieces in the oil. The gears are shiny and show a centered pattern with and without prussian blue.

I just found a very small, and I mean small click in the u-joint on the way to the store now.

New u-joint installed. New brake calipers install because the old ones were corroded and hardly working. Can't put new calipers in with new pads. Two and a half bills later= J.E.E.P.

Rotated the tires and took it for a drive. Noise was still there but at a greatly reduced volume. Think old Kaiser maybe on to something. Mainly because I have eliminated EVERYTHING else I think. Will look at new gears when I get it back from the next trip around the end of October and post the results.


:rotflmao: :rotflmao: :rotflmao: :rotflmao: Got to 'cause I'm tired of crying!
 

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Stinger said:
44K on the meter and probably another 40k being flat towed.
Wow, I may be on borrowed time for sure. (over 100K) Glad I have plans for the 1 tons soon so I can forget about it. Not everyone wants to do that of coarse.

When something like this happens under "load", in most cases it is a bearing issue/joint. Since you just replaced the carrier bearings, did you replace the pinion as well (can't remember if I read that)? what about the axle shaft bearings? Finding these kinds of issues are tough and can be enough to make the Pope swear.

Good luck.
 

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Update and lessons learned.
After "trusted mechanic" got done with the new bearings I narrowed down the problem to the locker because HE told me everything else was good. Called Dave and was seriously considering an ARB. In despair and just in case, I pulled the carrier one more time and tore apart the factory locker. I was convinced it had to be that because everything else had been eliminated. Locker was fine. :-x

By now the frustration level was just about out of sight!

My annual salmon fishing trip to the Oregon coast was upon me and the Jeep is our boat launcher. So I called Dave at Northridge on Monday and asked if he had time/room to do a rear end build. He said yes so I said be there Thursday morning. Actually got there Wednesday afternoon and turn the heep over to him. We went thru all the signs and symptoms and what had and had not been done. The possible problems were obvious and all meant $$$$$$$$$$$$$$$.

We camped in their new shops parking lot for the night (fabulous shop by the way) and the next morning they picked me up and hauled me back to the old shop for a look. HE “trusted mechanic” apparently had not bothered to do a tooth pattern check after putting in new bearings and fixing the shims because what Brian showed me was outrageous. There was an error of .023 in the pinion depth stack and the new wear pattern in the ring gear made it obvious why the noise was louder after the “fix.” Brian, who actually did the rebuild, had my new gears out with the tooth pattern showing perfect. SMILE. Test drive was so quite it was spooky. I am now about 250 miles into the break in and gears are still silent. More accolades for Dave and Brian at Northridge. Super service and a great price.
Long story short: “I have been doing this for 30/40/50 years” does not necessarily mean the customer should not check a mechanics work! When I pulled the carrier to check the locker a quick brush of Prussian blue would have told a damning tale.
:rotflmao: :rotflmao: All is well
 
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