Recently, my wipers stopped working on my '98 Civic. I got down to the source of the problem: the motor is working fine, but the arm that connects the linkage to the motor came off. A plastic "snap ring" of some sort appears to have broken so the arm won't stay attached to the motor.

Here's the diagram I am looking at:



So now I know the problem, but I'm a little confused when looking at the diagram for what specific part I need to order. Can I buy just the plastic ring (is that 8 or 9?), or do I need to buy a new arm that will have all appropriate pieces? If so, which arm connects to the motor (is it 11 or 12)?

Thanks a bunch.