Not sure what model you have
I assume its a Wrangler ? YJ or TJ ? it probably has Dana 30 Rear axle
these are common ( also in the Cherokee )
Once you get your estimate to rebuild the DANA 30 you might want to do yourself a favor and swap in a DANA 44.
If you plan to keep the Jeep... it is dollars well spent.
FYI be sure it is geared the same as your front Differential.