In article .com,
wrote:

It's more than just rudder stops. The stops themselves are strong
enough and don't get "deformed" much. The rudder hinges wear and the
bellcrank can get bent or loose in the rudder, and these contribute to
the rudder stop going over the stop head and getting caught. Once that
happens, there's nothing you can do from the cockpit to unhook it.
There was an accident here in Canada that resulted in a Canadian
AD forcing modification of the stops. A student and instructor were
killed when the rudder locked hard over when entering a practice spin
and they couldn't stop the rotation, thereby preventing spin recovery.
There's a Cessna Service Bulletin against the stops, too. Any
150/152 owner would be wise to get it checked out. There are a lot of
aging airplanes out there with worn-out parts in the rudder system.
Cessna sells a kit to install non-catching stops.

Dan

I was taught for both the 152 and the 172 that during preflight you
should push the rudder from stop-to-stop and verify that the stops hit
head-on and everything is secure.