Alternator cavity has engine oil

[Abbert55]

A week ago, the wife and were riding when the trike died, with no battery power left. I assumed the alternator had quit and ordered a new Hitachi repacement. As I pulled the alternator, there is a good amount of engine oil in the cavity. I read some posts here, but cannot quite convince myself that this is normal as some suggested. It is 32 years old, and I expect some territory marking, but this does not seem normal. The alt o-ring seal had been seeping for a time as evidenced by the grime left in that area. The question is: If this is normal, what's the purpose in having oil in the cavity since the alt is air cooled. Secondly maybe should I add some of the polymer stop leak to rejuvinate the rest of the seals given the age of the bike?

1991 SE 123,000 miles Roadsmith trike 2014.

[MikeB]

I am unsure what you are referring to as "the cavity". Oil in the alternator itself or oil in the engine where the alternator mounts? With the alternator removed, that engine is open and there is oil present. That is normal. That is the reason for the "O" ring around the circumference of the part of the alternator that goes into the engine.

If you get oil in the alternator, it is because the seal around the alternator input shaft has failed.

[offcenter]

With the alternator removed, that engine is open and there is oil present. That is normal. That is the reason for the "O" ring around the circumference of the part of the alternator that goes into the engine.

If you get oil in the alternator, it is because the seal around the alternator input shaft has failed.

I agree 100%. I've had this happen with TWO of the cheap chinese alternators. Oil got by the seal on the shaft and destroyed the alternators. Right now, I'm running a genuine Honda Hitachi alternator. So far, no problems.
There should be NO oil in the alternator itself. It won't end well.