Hole in transmission case!

td25c, Thing is if it is suppose to be a "dry flywheel housing" and it is leaking oil a patch like that would only mask the problem till the housing got so full of oil it would overheat the converter or push the oil out some place else.

I still thing the OP needs to confirm exactly where the oil is coming from before we get to excited about how to repair it.

No sense in putting a new roof on the house if the water is coming from a leak in the water pipe from the well!

Understand that Ken . Was throwing out ideas on a cover for the hole .

But like JohnC mentioned the machine has obvious leaks from above that aint coming from out of the hole in the housing . Notice the drips & oil washed housing .
The hole in the housing is a bit odd . It don't look factory and yet it don't look like it was from damage .

Pretty sure that is just a casting drain hole that didn't get a lot of cleanup on manufacturing... most of the 'blowout' holes I have seen on cast cases usually have a good taper to the edges not straight like that one, the last one I fixed with JBWeld owner wanted a cheap/quick fix... been holding several years on a 4 speed range tranny... side blew out a 2 inch hole from chips of gear teeth getting wedged in the case so I cleaned out what I could with a magnet and jbwelded it and told him to go easy on grinding the gears

sure looks like a torque conv housing drain hole to me.looks like maybe a front trans seal behind the TC went..time to check trans fluid levels, put a big pan under her and see. If something grenaded it woulda made a LOT bigger hole than that.

If my machine has six varieties of fluid, it probably leaks from ten places. If an old machine doesn't leak it is out of fluid.

I say that, but my Dresser is the one exception.
I've had, or have three Identical Cummins engines with very similar torque converters. Two leak steadily, until one got bad enough to need surgery. In my case, old tractors typically get used for an hour at a time. Leaking a cup is messy, but tolerable. On the occasions it runs all day in hot weather, oil gets thin, and leaks at a higher rate, is when I get alarmed.

These are not terrible to get to, if you have access to a grease pit, not unpleasant at all. A seal might be $20.00, A remanufactured torque converter might be $400.00.

Do take the advice of others in this thread, and confirm the leak is coming from inside first. This is the low point, A leak anywhere will drool off this casting.

Your tractor has a reversible fan. It could push oil forward, or rearward. It does not look like engine oil.