Washing machine has small leak

1996 Kenmore 90 series Wife noticed the rung under the front feet of the washer was wet. I let th e area dry and put 20-25 gal water in the basket (no leak) then spun it dry . No obvious leak. I tipped the unit back just past the balance point and looked underneath for water.

There was a drop of water hanging down from the motor and a lightly oiled m oist area around the center of the transmission. The wiring harness was we t but the pump inlet and outlet hoses were dry. Pics at:

After I set the machine back down, around 4 oz of water puddled in front of the machine. I just looked at the exploded parts diagram and see under th e tub "Gasket, Centerpost Switch" which I presume I must replace. Does thi s sound right? Do I need a special wrench to remove the basket? Bob