After replacing the drive chain with a stiff link in it last week, and
reassembled the planer, I ran a few test boards through. First one
went through ok. Second one, the planer resumed its "thunk thunk
thunk" leaving divots. This time I completely disassembled the planer
and found bushing for the roller in the exit side of the planer was
almost completely worn through. In fact, there was a stress crack in
one side of the bushing. I could probably peel open the bushing if I
tried! I guess the stiff link in the chain caused the spindle to pull
up & down until it wore the bushing out?

The amazing thing is that I have not run that many board feet through
the planer. Doing more research, it appears this is not an isolated
incident for these bushings to fail - they appear to be aluminum?

In any case my question is: since I am replacing the bushings, I
probably should replace the rollers/spindles as well, right? Since (I
would think) they would both wear evenly, particularly the one in the
back that wore through the bushing?

Cheers,
Dukester