If the washer moves when you pry it with a screwdriver, it's loose enough.
Button it up, put the road-wheel on. Grab the wheel at 12 and 6 o'clock, wiggle wiggle wiggle. A small "click" is great, a large "clunk" is too much play. No "click" at all may very well be too tight, which is also bad.
914 and 911 front wheel bearings will loosen up if you load them up enough. Autocrossing will make them looser and looser, and after a while they need to be tightened.
I've done the wheel bearing adjustment in 20 minutes on the "false grid" at Candlestick. To a competitor's car. (The bastard had the nerve to out-drive me after I got his car to pass tech!!! Imagine, being more skilled than me after that!!
)
--DD