I'm shopping a Johnny Mnemonic (not my first rodeo, my eight shop job). I've stripped the top of the playfield and removed most components from the bottom. I've disassembled most of the mechanisms and tumbled all the hardware. I've got notes good enough to surely get everything back together, but the differences among washers have always sort of escaped me.

The two most common types of washers are nearly the same size, but come in two flavors: thin and thick.

I'm looking for the general rules of thumb about what washers go where. (An example of a similar rule of thumb for screws: the hex headed wood screws that are everywhere on the bottom of the playfield come in two different length, the shorter ones are gold-colored and used to attach lamps, the longer ones are silver-colored and used to attach switches and mechanisms.)

(Edit: the rule of thumb seems to be that the thin ones are used below the playfield between the playfield and nuts for attaching posts and stuff. The thick ones go above the playfield on posts and stuff.)

If I only knew the rules for the two most common washer types (thick and thin), I'd be very happy, but to dig deeper, I've sorted my washers into eight different types, taken a picture, and numbered them. Here's more info about each size.

1. "Normal" size. Thin. Quite numerous. (Edit: probably underside of playfield between playfield and nuts)
2. Normal OD but smaller ID. I only have 5 of these. (Edit: probably pop bumper rod and ring.)
3. Normal size. Thick. Slightly smaller ID than type 1. Quite numerous.
4. Larger ID and larger OD than type 1 or 3. Thick. Only 2 of these. (Edit: slingshot arm)
5. Same ID as type 4, larger OD than type 4. Thick. Only 1 of these. (Adjusting posts near outlanes? I was missing one.)
6. Big and thick. 6 of these. I know that these attach the playfield rest bracket and playfield hangers under the apron.
7. Smallest of all. Thin. All show markings from star washers. 6 of them. (Edit: trough opto boards)
8. Biggest of all. 2 of these. I know that these protected the bottoms of the slingshot plastics.

Anyone who can provide any help will be my hero! Thanks!

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OMG I think you're right about everything.

Thank you for amazingly good information!