Mercury Outboard 850 thrust washer behind reverse gear seems loose/too much play

Rebuilding my Merc 85hp's gearbox and the reverse gear thrust washer seems to have more play than 'normal'(?). I'm concerned that it won't hold the o-ring proud enough for a positive seal, since it presses the ring back against a sloped surface that forces it out against the inside of the case housing to seal it off.
I can measure approx 2mm between the back of the rev gear and the washer. Is the to be expected? I gave some raps on the gear to make sure it was seating in the bearing properly and it didn't budge.
Thoughts?
Thank you

I attempted to attach a picture, but I'm not sure if it worked

The thrust washer sets step in housinfg when slid in, when you tighten carrier it pushes o-ring out to the sides sealing carrier to housing. The space you refer in normal

faztbullet said:

The thrust washer sets step in housinfg when slid in, when you tighten carrier it pushes o-ring out to the sides sealing carrier to housing. The space you refer in normal

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Excellent. Thanks for your quick reply, and the good news.