Can this be fixed at home?

If it came undone,, it's possible the crush sleeve was never "crushed", so you may get away with just retightening to... 240 lbs/ft.. or until there's preload on the brgs of 20 -30 inch/lbs for new brgs or 0- 15 in/lbs on an old brg....

(I'm prob gonna hafta put on my fire suit again.. lol)

Were I you,, remove the "pig", don't be alarmed if the carrier is a bit chewed up by the pinion,, but it's important to clean any chunks/shavings outta the housing, change oil etc,,. and make sure the pinion gear doesn't have any seriously chipped/missing teeth,...

and I would urge you to take it back..

hope it helps..