Too much oil? aka Duh moment.

[Geom]

Ok, I've had my first (significant) duh moment, of I'm sure many more to come.

We were prepping our bus for a trip and I did the usual walk-around check, got distracted, and forgot to check the oil level. I started the bus and everything was fine.
Then I remembered that I hadn't checked the oil. So I decided to check the oil; while the engine was running (duh). Anyway, it was, obviously, showing very low oil. Panic! So I went up front, killed the engine and proceeded to dump a bunch of oil in it. After checking it a couple of times, while continuing to add more oil, it suddenly dawned on me how stupid I was being... 

Anyway, with the engine off, the oil returned to its previous (full) fill level, plus all the extra I added in.

I have, what I believe to be, an extra 2 quarts (or more) in there; before the duh fully dawned.
The fill line is well above full.

So now my question. Is it harmful to have too much oil?
It doesn't seem like it should be an issue (other than peeing oil everywhere). We've taken it on a couple of short (under 1 hour) trips this way and it ran just fine. Oil pressure looked good, temps looked good, everything sounded good. I just want to double check, in case leaving it in there was somehow doing long term damage.
I would've figured it would have blown the extra oil out, but it's managed to stay at the same (overfull) full line for a little while now.

Thanks in advance,
George

[Cary and Don]

Well George, you are lucky on this one.  You have a quick drain valve on the bottom of the pan.  You can pop it open and drain some of the oil out. Drain some out and check after it sits about ten minutes so the oil in the engine can drain down into the pan. We always keep it just below the full mark.

Don and Cary

[Geom]

Sweet!
I will look for that when I'm over there next and I'll take an oil drain pan with me.
Do you think I should actually drain the extra out, though? Do you think that it's bad for it to be in there?

Thanks
George

[Cary and Don]

Better safe than sorry. I would get it down to just under that full mark. While you are under there, remember that little air box drain tank?  Just unscrew that big nut in the bottom and let it drop into the pan. Drain that too if you haven't.

Don

[treeplanter]

To much oil will cause extra resistance on the rods,

[Lin]

I do not think that two quarts over would be a big deal.  It's the "or more" that would concern me.

[Geom]

ok, so it sounds like I should drain the excess oil as soon as I can.

Don, I agree with you that it's better safe than sorry. Plus you're right, I will likely need to drain that air-box tank anyway.

Lin, the 'or more' part is a result of just dumping oil in there in a stupid panic. I started out with a mostly full gallon container and ended up with a mostly empty one, before I solved my anal-cranial-inversion problem. So it's likely 2-3 quarts.