6MT differential replacement question

[audiodenker]

Hello,

I have a 2010 legacy 2.5 6mt. It started making a scraping ,thumping noise while driving that increased with vehicle speed, independent of gear or clutch position. cv shaft was replaced and did not change noise. the dealer listened to it and said"excess bearing noise in transmission". their solution-replace transmission...upon further investigation i found the bore in the differential where the cv joint inserts is scarred and worn. I found a used one that is from a older 5MT trans. Do i need an exact replacement from a 6MT or are the differentials the same throughout 5MT, 6mt, or from 4th gen to 5 gen.

best regard,

Richard