Hello - attached are the four photos I took plus one I marked with dimensions (in red ink).
Here are what I got for dimensions:
2 3/4" Length of roller body
1 5/8" Height of body
5/8" width overall
1.5" Diameter of roller wheel
Hope you can read & see these OK.
The sliding door is at least 22 years old (Pella Brand) and it has gotten harder to open even when I take door of and clean and grease both roller and track.
My info:
I am both Military and 65 years old if you have any discounts...and thanks so much for your help!!
Reed (who may not actually be that quick of a learner).