Good day

About a month & a half ago I started hearing an unusual noise in the rear underside of my truck.
My local garage has checked it out & confirmed with a stethoscope problems in the rear end.....so rather than remove the crown & pinion & related bearings he has suggested getting a used rear end & just swapping out old for newer.
Has anyone ever heard of rear end failure on a Silverado with 149K.....92000 miles? It seems to me to be very premature.
Would there be any warranty on the drivetrain that would cover this?

Any help or advice would be greatly appreciated.

Thanks