What is this hole? Possible gearbox leaking oil?

[Ph1Rich]

I'm posting this on behalf of a mate of mine who has recently bought a 172. He noticed a large pool of oil on his drive after a spirited drive. This is a pic of possible damage.

Any thoughts?

Any help is appreciated.

 

[MicKPM]

Yeah that's fucked!

New box required i'm afraid.

 

[Mr R.]

Fcuking lols, its fcuked.

 

[MartinR]

Cow me!!

Mick any ideas on what causes this? Have seen it a couple of times on here now.

 

[Ph1Rich]

Right. That's cleared that up. As above, any ideas on how its happened?

 

[MicKPM]

Hard to say without a strip down but odds are on either over-revved or a bearing failure (due to years of neglect). Could've even been Foreign Object Damage such as part of the drive shaft spider rollers or some other crap in the oil.

 

[DaveDreads]

It's a speed hole, makes the car go faster.

 

[Owen92]

FLOL. I'm pretty sure the jagged edges make it obvious to everyone that it's fucked.

 

[MonkeyKnifeFight]

^^^ Usual Renault casting finish

 

[Dan@SJM]

In my experience it's the planet gears getting scared of the dark and shearing in half, then getting trapped between the main diff casting and the gearbox outer casing and then breaking free.