Parts #10 & #11 are pushrods that operate the cranks on the motor & the wipers. They should have some kind of bushing in each end of those pushrods. Look to see exactly where the looseness is located.

It seems likely that some of those bushings have got loose, worn, or whatever. But you probably have to buy the pushrods 'cause it doesn't look like the bushings are separate parts.

 

Changed parts 10 and 11 and no more play! Thanks to all.

Jim