I just assumed they went on the outside, just under the clip - but now reading Dwayne's post, I'll go back and look at the centering.
There won't be much play, but even a little is problematic from what I read
here.
BTW, play in the shaft itself moving in and out of the hydro is normal, so don't worry about that. We're talking about the outer plate moving in relation to the inner bracket. That should be snug.
Remember, I was only talking about .040", so that is "not a lot." And I didn't file a standard washer, they're way too thick (although, I guess you could...) I started with this 18 gauge washer, or "bushing" as I think it was called at the hardware store.