I have a stupid question

[mr.jones]

I know them as a dust cover

[Vombil]

I know them as a dust cover

that makes better sense

[Frosty]

Thank you but there must be a more technical name, lower bell housing cover? Clutch inspection cover? Why would it be missing anyway? I doubt that I would care except that it may not pass a road worthy inspection which I'm about to do.