C pin on the speed dial Kenwood Che4f A701A?

Can you advise me if there should be a C pin on the speed dial of the Kenwood Chef A701A my machine wont go on slow speed at all only high speed, when I look on the inside from underneath it does look like it has some of the plastic broken away or off, there is a hole going through the shank my husband seems to think there is a C clip missing. Can anybody help please, I would really appreciate it.
thanks.