drain must be freezing some where, when water is added it thaws and may cause gurgling,
Master plumbers.
Cut out the old piping and caulk a new cast iron bell and spigot with lead and oakum and test.
a plumber
Very carefully drill a hole by each end of the split then gently grind a "V" shape in the split and then use a Cast Iron welding rod AFTER pre heating the base mental and allow to cool naturally as...
With an 11/2 Mission coupling toque to 80 in pounds.
How to Fix Clogged Drain
How to Clear a Clogged Drain Pipe
Plumbing - Gluing PVC Pipes
How to unblock a kitchen sink and waste pipe