[Shop-talk] Retaining ring pliers?

[Randall]

Tough to say for sure, Jim, but that looks similar to the retaining ring
used on my Triumph starters.  If it is, then the collar cannot slide over
the ring.  Instead, you have to push the collar back from the ring, and pry
the ring out of it's groove first.  Once it's out of the groove, the collar
can be used to force it along the shaft.

I have never found a tool that helps, other than a couple of cheap
(sacrificial) jeweler's screwdrivers that are thin enough to work in between
the ring and the groove on the shaft.  I clamp the armature firmly in the
vise (using smooth, relatively soft metal jaws to avoid scars), then use my
left hand to both push the collar back and position a screwdriver so I can
tap it with a brass hammer and drive it between the ring & shaft groove.
Then pry the ring out, working around the shaft.  Not an easy process.

-- Randall