aaaargh! daughters prisine sx has no reverse

[tri again]

Most dependable, babied 85 sx of the group.

Neutral light acted a little funny but seemed to have neutral
between 2nd and 3rd.

so I rocked it and got true neutral and N light.

Started right up.

Tried for reverse and heard the faintest gear grind like it wanted to go into reverse
but it stayed in neutral.

Thought about trying regular forward gears but thought it not to be a good idea if
something came loose or broke.

Any refreshers on the recent posts about some pin that breaks or bends
and goofs up the shifting?

I've heard it's time to take the side cover off and you'll SEE it.

but not even sure what side cover to take off. Left or right?.

Gonna hafta find a cover gasket and whatever pin or spring and it's also the weekend so parts places are closed.

Where do we even find these?

ps - reverse linkage from hand lever to gearbox feels, throws and acts normally, btw

Thanks everyone.