Answer
How do I fix a wobbly fence post?
Re-set the post properly in concrete, or replace it; the base has usually rotted or failed.
In short
A wobbly post usually means the base has rotted or the original setting has failed. The lasting fix is to re-set the post properly in concrete, or replace it with a concrete or oak post, rather than patch it. The posts are what hold a fence up, so they are worth doing right.
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