5 Speed Transmission Side Gasket?

[Gambit]

I've got a small leak with my transmission, just a drop or so after a long drive. But I'd like to take care of it while it is still small. My question is - is there an actual gasket here? Or should I just use some sealant that comes in a tube? Anything I should be aware of before removing this and trying to seal it... random gears falling out or ???. This may be a dumb question, but I'd feel dumber if I opened it up and half the transmission fell out. This is an '88 5spd 4wd if that makes any difference. And thank you!