Toyota Repair: front end whine when driving 2003 corolla, mile test drive, differential gears

Question
QUESTION: 2003 corolla auto trans/30,000 on odometer. Was hit & repaired on the right side - salvage title (still has origional doors/hood/skirt/strut etc).  Whines while moving foward - (if it was an old detroit car would suspect ring & pinion noise).  Whine stops when car is not moving. CV boots look good. Pushed & pulled front tire/wheel bearing felt tight & not hot (after three mile test drive)  What fails & whines (up front) on these cars. Thanks for your time. Bill

ANSWER: It's differential noise, it does have a ring and pinion gear in the differential just a little different than the conventional differentials, a whinig noise from the transmission is almost always caused by differential failure, either the bearings or the gears.

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QUESTION: Labor time (hours) / cost guestimate. I've never taken one apart.  Thanks for your time, Bill

Answer
It takes some special tools to repair/replace the differential gears, in most cases the metal particles from the failing differential will enter the transmission because on corollas both use the same fluid, there is no seperation between the two. We usually just replace the transmission.