Oil or grease stain on clothes when washing clothes

Your transmission seal may be leaking oil into the tub. This is not an easy fix and it will get a lot worse in a short time. Before you do any repair or replacement try running a load empty with plenty of hot water and detergent. Now run a load with some white towels, rags or sheets to see if you still get oil stains. If the stains are present you may need to call in a pro or replace the machine if its getting old.