Ranch on slab, bathroom remodel, drain question

[ebaer]

One of the bathrooms is being remodeled and the tub will be replaced with a shower.
We assume there is a drum trap down there but we went a foot under the slab and still nothing.
This all cinder block 1965 rancher is very long and we are at the end of the house where the main waste pipe leaves the house so it is deep. We were able to use a shop vac and remove some what looked like metal pieces of a spring and other gunk from the drain. Am I worrying too much and should just leave the old trap in there?

 

[Terry]

You are are installing a shower, the drain will be moved. I think you should dig a bit more and expose the p-trap.

 

[Sponsor]

 

[hj]

The drain to the old tub is probably 1 1/2" so you would want to increase its size for a shower.