That is a snap ring. There are two kinds of snap rings, external (grips around the outside of something) and internal (grips around the inside of something).
External snap rings must be forced apart to release or install them, internal snap rings must be squeezed together. Some snap ring pliers can switch the pivot point to do both, sort of like slip-joint pliers.
Take the snap ring to Sears' tool section (1st choice) or your local indie auto parts store (second choice) and make sure the snap ring pliers you buy are big enough (and are the right type) to do the job. One decent adjustable Craftsman internal/external snap ring plier should run you no more than about 20 bucks at most.
Don't buy the cheepie taiwan/china pliers as the tips will snap off when the ring is under the most stress, ruining the tool and firing the snap-ring off into the next county, never to be seen again. Hence, the nickname "Jesus clip".
Stiles
Oakland, CA
November 2002
OCT 05, 2005 07:26 PM