• Gear Dog Damage: Inspection and Causes

This section is not meant to be a replacement to the FSM.
It is meant as a compliment to the FSM with added information with pics that are not in the manual.
Always buy an Factory Service Manual AND a Factory Parts Catalog to help you along your maintenance path.
The Haynes and Clymer brand service manuals for the most part will suffice and they generally have more pics than the HD Service manual.
But the HD manuals will be the most accurate.
All in all, there are discrepancies in all of them including the HD parts and service manuals though.

With some of these parts, finding imperfections and cracks requires more than just glancing at them for obvouos damage.
Thoroughly cleaning the parts/gears from oil and debris and close attention to detail will do you well.
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Inspect every tooth and dog on every gear with a magnifying glass or eye loupe. ²⁾ Cracks or pits go in bad pile.

Some are obvious, some are hard to see on a quick glance as shown below.
When finding damage to a gear's teeth, always check a gear's corresponding gear's teeth when you find damage.
Replace both gears as a set to avoid the old gear's teeth damaging the new gear's teeth.

Here is a MS 2nd gear with a crack on the lower edge of 1 tooth and dings on it's other gear teeth.
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