HOLE IN MY GEARBOX... Should it be there???

[H15DTL]

Just taking the intercooler off the Leon and noticed there is a perfect round hole on the top of my gear box next to the linkage that either hasn't got a bung in or shouldn't have a bung in but I can see through it what looks like the teeth to my DMF...? Any advice please? Tried to up plaid a pic but won't let me

 

[mad-for-tar]

Think that's the viewing hole to find timing mark on the flywheel. Covered by the bung 02M301115B.

 

[googujube]

Pepper your angus. Think these are about 8 quid from the dealer.