How to tell if it's a slipper clutch

Many 912UL's didn't  come with slipper clutches and depending how old the engine is may have a 15 degree vs 30 degree gear setup. What year is the engine? Some owners added clutches on UL's

Hi Gil,

If I remember correctly there is some bolt one can stick in a particular hole in the engine case to block the crankshaft. Do that and try to move the prop in normal operating direction. No movement, no slippery clutch. 

Go to the current maintenance manual line, MML, section 12-20-00 find where locking of the crankshaft is shown.  With the crankshaft locking pin in place then you can go the the propeller and try to turn in in one direction and then the other.  If there is no movement other than gear lash you have no clutch.  If you can move it 30 degrees you have a clutch.  There were only a small number of gearboxes from the 1990s with a 15 degree so it is unlikely you would have one of those.  If you did I would change for the 30 personally. 

Cheers

It was new in 2017