[Sevenjays]

Hi, I've had noise in the rear end of my 06 Commander with QDII since I got it. Seems to be getting worse. Sounds almost like a brake dragging at low speeds, under 30 mph, and then a noticeable howl/whine at 70-80 mph. Definitely comes and goes when under power/coasting. I opened the cover and didn't see anything obvious. Serviced with Amsoil. It does leak a little out of the front seal. I've put about 12,000 miles on it since I got the Jeep. Total miles are 140,000.

I'm trying to decide between:

Recycled(salvage yard) complete rear-end with 132K on it for just under $700 including tax. Possibly end up with one just as worn as mine.

Or bring it in to a shop and hope they can get it fixed for $$$??? Basically, leave a blank check. Labor adds up quick.

Any recommendations?

 

[jeep5253]

@Sevenjays Did you put the Mopar friction modifier in it?

.

 

[Sevenjays]

Yes, I did use the friction modifier.

I decided if I'm leaning towards ordering a different one, what's to lose in at least getting into mine and seeing what I find. So I pulled the wheels, brakes, rotors, driveshaft, and rear diff cover.

I did find a small parking brake rub noise on the passenger side. I'll back the shoes off for the next test drive, but that noise should be constant regardless of if I'm on the gas or coasting.

There was still a lot of fluid and it didn't sparkle with metal flakes.

No visible abnormal wear or broken pieces.

Pinion flange has no play.

In reading the service manual, the high pitch noise/whine at highway speed could be:

REAR AXLE - C213RE
GEAR NOISE
Axle gear noise can be caused by insufficient lubricant, incorrect backlash, incorrect pinion depth, tooth contact,
worn/damaged gears, or the carrier housing not having the proper offset and squareness.
Gear noise usually happens at a specific speed range. The noise can also occur during a specific type of driving
condition. These conditions are acceleration, deceleration, coast, or constant load.
When road testing, first warm-up the axle fluid by driving the vehicle at least 5 miles and then accelerate the vehicle
to the speed range where the noise is the greatest. Shift out-of-gear and coast through the peak-noise range. If the
noise stops or changes greatly check for:
² Insufficient lubricant.
² Incorrect ring gear backlash.
² Gear damage.

Or:

BEARING NOISE
Bearing noise can be either a whining or a growling sound.
Pinion bearings have a constant high pitch noise, because it rotates at a faster rate. This noise changes with
vehicle speed. If noise is heard under a load, the rear pinion bearing is the source. If noise is heard during a coast,
the front pinion bearing is the source.

I'm a bit intimidated by the idea of replacing pinion bearing or adjusting ring gear backlash, but those seem to be the most likely suspects.

I'm not sure when I'll be able to dig deeper. I think I'll have to gather a few tools before proceeding further. I'll report what I find.

 

[Hawkeyes]

Just went through something very similar...have you checked the ujoints?

 

[Sevenjays]

Just went through something very similar...have you checked the ujoints?

I didn’t have any play in the u joint at the rear diff when I disconnected it, but I’ll look at it closer before I take any more apart on the pinion.


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[Hawkeyes]

Everyone said my ujoint was fine, still says it's fine...but I still get that sound if I put the old one back in and only that one. Definitely was mine. Still able to move them as they should. One does feel kind of "sluggish" I guess I would say. I'm going to replace them in case my double cardan takes another dive.