[Pd154]

Is this for lubricating the shift linkage? About to put in this 5-speed where the auto used to be in 2001 beetle and cleaning it up. In the hole I can see linkage moving but it's not a greese nipple so not really sure. The plug is beside it there held in pliers.

 

[billymade]

I believe, that is a breather cap; from more info, look @ page #9 here:

http://vwmotorsport.com/vwtech/gears/mt_02J_overhaul.pdf