This happened to my mates gearbox, he's currently running a 2.0 16v Turbo. Its currently only running at half its power (for very good reasons)
The fifth gear seems to half just exploded
Some teeth from 5th gear.
Yes if you look carefully there is a hole in the end cover.
Luckily he happens to have a 2.0 16v GTE on his drive doing nothing. So he has used the gearbox from that.
After a long weekend it is now back on the road...
His post on mig can be found here
rough_neck