replacement rollers on my sliding glass doo

That code number you gave might mean it was manufactured in 1986, but I'm not sure. I'm afraid without seeing the roller itself out of the door, it will be difficult to make a confident suggestion. I will try my best, though.

If your door was manufactured in April 1982 or after, then you will need to use the newer style 81-128. If your door was manufactured before April 1982, then the older style 81-018 would be better.