Gearbox Problems 912iS

I think if most of us opened our gearboxes we would see similar wear. I know mine looks exactly the same with two hundred hours. As the manual states, “A certain amount of wear is permissible “ . Probably why the magnetic plug goes into the gearbox.

Ed

Malcolm,

Earlier the question was asked “what kind of oil was used”, but I did not see an answer to that. 

Sorry missed that, we have always used Oil AeroShell Sport 4 Plus

Interesting topic....please have a look again at the dog and also look at the main gear.  I note from your picture that only one dog contact has wear, the other two seem without contact.  If this is correct you have a misalignment of the dog and gear.  In general when this is seen in a standard ULS with clutch I would recommend a change of the gearset and the dog (always replace the dog if you change the gears)  The spalling on the ramp is not the issue and is somewhat normal.  The vibration appears from the picture to be a mismatch of the dog and gear

As a note, whenever you take one apart you need to index (mark) the dog to the gear.  When you reassemble they have to go back to the same position to avoid accelerated wear.  After first use they mate together so we want to avoid changing the wear points in the dog and gearset. 

Cheers

Just to be clear I have made some notes on your original picture to show you what I a looking at.  The 7 degree flat areas must ride evenly on the gear or vibration will develop in my experience.  

Cheers