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Discussion Starter #1
I'm hoping somebody can help me cure this problem.
When the differential lube is hot, like after freeway driving, my 9" Auburn posi groans loudly on corners. It's done this since new and still does it after 5000 mi. Lube is as recommended - 90W plus additive.
Is this normal with Auburns? Should I change to a heavier gear oil? Release torque is correct and the unit works fine. It's just embarrassing when the damn thing groans and passengers think a wheel is falling off!
 

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I have a Auburn Pro iin my 8" rear end. It is quiet most of the time, only makes noise if I'm backing in a tight circle. It never makes a groan sound.
 

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Discussion Starter #3
Bill, do you use 90W in there? This is what they recommend but it seems thin to me.
 

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In my 9 inch with 3.50 gears and Auburn locker it NEVER howles or growles. When pulling away from a light or stopping at a light there is one pop noise from it and when turning corners at very slow speed there is a noise like Korunk, korunk. This is when it has to unlock to allow the wheels to turn at different speeds. I have about 15K miles on it. John
 

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Discussion Starter #7
John, yes, definitely clutch noise. It's loud though, resonates thru the body as a continous squeal as the clutches slip, only when the diff is hot, only in those slow corners. Think I'll try Redline 75W90 like BillGear said he uses & a different additive (friction reducer).

Thinking about drilling/tapping a diff drain hole. Anybody know the SAFEST SPOT TO DRILL?
 

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Discussion Starter #8
Pete, my noise is clutches, yours sounds like gear howl aggravated by thinning hot oil. I've read that some howl is OK, but if it is loud, you might first try a synthetic lube and then consider gear realignment.
 

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Ken, Thinking more about the noise there is a small whine as it does it's Kurunk Kurunk sounds. Only at low speed and only in corners that are tight. I had it installed with the 3.50 gears in your neck of the woods in late 99 at Rearend Specialists of San Jose. After the specified break in period I returned it and had them change the fluid and friction modifier.
Good luck and let us know if the change of lube helps. John
 
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