Ring and pinion gears are replaced as a matched set- - - -not individually. Chances are you've only got a failed pinion bearing unless it's been run for a long enough time to get gear damage. It's going to require a full teardown and cleanup, as there are two bearings on the pinion gear, and replacement of the inner one can't be done from the outside.

I'd strongly suggest finding someone who is very femiliar with rear end repair to do the work- - - -it's a complex operation with a lot of opportunities to make expensive mistakes.
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
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