|This ring retains the 3rd gear on the mainshaft.
The final design for this part came in 1956 and it has lasted all through 1984 and probably beyond.
Do not confust this with the snap ring that retains the washer and roller bearings for the mainshaft output bearing.
The Iron Sportster mainshaft is a triumph of engineering. The general design has sustained from 1952 to 1984. There were teething problems in the early K-model, but they were all cured by 1957 with the introduction of the Sportster.
The mainshaft retainer ring is in the darker oval.