In this NASA document, it is mentioned on page 221 (239 of the pdf) that a "23 tol gear box" was used. What does that mean?
A google search for "23 tol gear box" (with quotes) comes up completely empty, and "tol gear box" shows only irrelevant results. A search for just tol doesn't come up with any convincing results either. I can't rule out that it is a typo of some sort.
From the context I presume it to mean that the gearbox output runs 23 times as fast as the powered side, but I have to be certain.