I found it.....look carefully at your filler cap. There is a small hole that is on the side of one of the 'wings". Then look at the bottom of the cap and you will see a small hole near one edge. I had to clean mine out with a needle and air....25 years of "gunk" and crud.....look carefully and you will find it.
Thanks. I looked on my cap but no hole is there so I drilled on with a 3/16 drill. Ran the tractor for four hours and no oil is venting out the shifter areas. This is where it was most noticible.