Time to play "What's That Noise?!?!?!"

[Ted Striker]

2021 Texas Trail. 2.5" Clayton lift, 37" Ridge Grapplers, Yukon 5.13 gears, no lockers.

I've been hearing this noise for a few months now. I suspected it was the rear gears at first, so I had 2 different shops look at it, the shop that installed the gears and another independent shop. Both have said the rear gears look great and are meshing perfectly. Now I'm wondering if it might be something else - possibly a bad wheel bearing or maybe the front gears? The noise is most prevalent at 45-50 mph and steady speed. It goes away slightly if I let off the gas pedal, but you can still faintly hear it and then definitely hear it when I press on the accelerator again.

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[Hootbro]

How are your pinion angles with the driveshaft? If stock two piece rear is still used, did a drop bracket for the center carrier bearing get installed?

 

[Ted Striker]

How are your pinion angles with the driveshaft? If stock two piece rear is still used, did a drop bracket for the center carrier bearing get installed?

yes. I installed a rock jock carrier bearing spacer.

 

[Mball488]

Definitely coming from the Flux Capacitor. Try adding some banana peels and empty beer cans. Should do the trick.

 

[Tiny]

Definitely coming from the Flux Capacitor. Try adding some banana peels and empty beer cans. Should do the trick.

Assuming he's installed the Mr Fusion mod...

 

[21WhiteRubi]

Following along here instead of starting my own thread. My hunch is that it is coming from the Yukon gears. I have a '21 rubi with a 2.5" AEV lift and 37" KO2s. I have been to Moab and back, as well as to Indiana and back (I live in GA) on the stock 4.10s. No issues other than hunting a little between 6-8th gear and really struggling up the pass in CO in 3-5th. But no noise.

Knew I was going to go to 4.88s and decided to have my local Jeep/4x4 shop do the install. They use Yukon almost exclusively.

Initial test drive was fine, no issues. When I started to finally get up to higher speeds (48-55) I started to hear the same noise as you are experiencing, only under acceleration. Never got over 55 mph in my break in period. Called the shop and brought it back to them (had roughly 200 miles on the gears). Tech drove it and said he hears the same thing. Opened things up and gears looked perfect. No metal, clean fluid etc. I event took my heat gun and tested them every time I went for a drive. Never over about 140 degrees at the rear diff cover after any amount of drive time.

Shop said they would get a replacement set of gears and a new bearing kit. Warrantied the gears with Yukon. Got the new set installed early this week. I still have the noise but it's not as loud. But still hear it at about 48-55. I am heading to Chattanooga this weekend (90 miles one way) and plan to take all back roads to keep things under 55. If the noise stays there or increases, I will be taking it back and asking to swap to Dana/Spicer gears.

From what I have read here and elsewhere, Yukons seems to be the culprit and once people swap to Dana/Spicer, no more noise.

Let me know what you find out about yours.

 

[Rusty PW]

I heard the stories about Yukon gears making noise for years. It seems to be hit or miss with them. Take the diff cover off, and everything looks fine. People swap out to another set of gears and it's fine. I don't know.

 

[SuperUltraMan]

Have you looked inside your tailpipe because it might be Gremlins?

 

[Rusty PW]

Have you looked inside your tailpipe because it might be Gremlins?

Nah.....that's muffler bearings. Gremlins were made by AMC.

 

[Steven_B]

Did you ever figure it out?

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