Look on the axle itself where they ride in the bearings. If there's pitting on the axle, that's a sign of bad bearings. And if it's too bad, I would wanna replace the axles themselves too. Because if the pitting is really bad, it'll just eat through bearings like it's nothing. No pitting, I wouldn't even worry about new bearings. BUT, they are cheap enough that you could do it all without breaking the bank. Your callAwesome. He had mentioned that the right axle seal was leaking a little bit, so I figured I'd go ahead and replace both while it's easy. I also figured I'd ask about the axle bearings sine they're so easy to get to once the axle seals are out.
If anyone else has more things to watch for please chime in.
Pull off the cover and look at the oil.
If the oil is water free, you should be fine.
They will last much longer than 3 years if stored inside.