Bozo stopped by the shop today

[durableoreo]

You cannot change gear tooth length to compensate for a center to center mismatch. The O.D. of a gear can vary slightly because it doesn't mate with another gear. Just as you can decrease the diameter of a screw thread slightly and still have a working thread.

It's the pitch diameter that must be maintained to acceptable tolerances. A deeper root or a smaller o.d. just increases clearances althoughit can have an effect on tooth strength if it strays too far from the design specification.

Am I misunderstanding addendum modification?