Have to move shower drain about 3 in

I have to move the shower drain about 3 in to the back wall. The old drain was 16 1/2 from back wall and the new drain is 13 1/2 from back wall. I have enclosed pictures. It is all case iron. Really do not want to cut more of the beams as is shown. I understand I will have to take out cast iron. Not sure how to move drain the 3 in. Sorry I can not take back shower base that would be easy way out. It is the color wife picked out.












Previous starting thread..... how-remove-drain-in-stall-shower

 

Sorry, we don't know what direction it needs to move. You know where the back wall is, we dont. Will everything sit the same way, but 3" shorter? If so, get a new 2" pvc trap and some 2" pvc pipe and a rubber shielded Fernco fitting. Cut the galvanized pipe back as needed... slip the Fernco on, then your new pvc pipe and trap will go in that.

And what's the white tape on there for?

 

I see no cast iron, just galvanized steel pipe.

 

I added some markings to the third picture. You're either going to have to disconnect that pipe at the connection by the red arrow or cut somewhere between the blue lines.

 

First is my concern about the joist that's notched way too deep. No inspector will approve that. I am sure many of the other joists where that pipe runs are also notched way too much. I would address that structural issue before proceeding. I'm sure it won't be easy and you probably not like what you have to do.

While you have the floor opened up I would remove all the galvanized steel you can. It has a bad habit of rusting through the bottom. Then it's easy to run the line wherever you want with PVC. The transition from steel to PVC can be made with a shielded Fernco (rubber boot) coupling like PJmax mentioned.

 

I agree. While you have it open, get rid of as much galv steel as you can. Then it should be eazy peezy to locate the opening where you need it.
You want the project to be a legacy, not a liability.