Help with 1993 Explorer part

1993 4dr 4WD V6.

I had front end-work done on my car. The mechanic,
whom I know well, said my front hubs had 2 plastic
washers (2 on each side) that needed replacing,
but he couldn't find "just the washers." He's called
around and everyone told him that the only way to
get the washers is to buy the whole hub assy., a
$300 cost. Needless to say I said leave them for
now since I don't currently need/use 4WD.

What are these washers called? Who can possibly
sell "just the washers"?

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- Zilla
Cary, NC USA
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