What is this? -TYM 330 hydraulic

[NWtractor]

Does anyone know what this is?
It is located on the BOTTOM of the front transmission on a TYM 330 (shuttle shift).
The 'stem' in the middle rattles around - there is no spring and no seal.
I had oil dripping from here and need to know if this part is missing something and what its purpose is. thanks-

 

[Leejohn]

Not missing anything, it's your trans case vent and drain. If oil is coming out of it you have a bad crankshaft or trans case seal/gasket

 

[NWtractor]

Leejohn - Thank you - very helpful.