Rancher oil leak

Hello all, new to the forum and just picked up an 03 rancher 4×4 manual shift. After a couple hrs of my sons and I joyriding around the yard we parked it in the garage for the night. The next day after pulling it back out I noticed a baseball size oil spot there and a drop or two in the driveway where it was sitting. Looking underneath there was oily dirt around the bottom of the recoil assy and the bottom of alternator cover. The only place there was a drip was on the plastic cable clip under the recoil. I’ve read that the oil seal will leak when dirt gets in there so I took off the recoil assy and it looks pretty clean. I didn’t remove the nut with my impact yet because it was getting late last night but I’m wondering can the seal still fail without being corroded from the dirt and mud or should I look at replacing the gasket on the alternator housing since I’m what looks to be halfway there? Anyone have to change that gasket for a leak? Thanks for any advise.