912 ULS Crankshaft Nut Torque Question
Hello all,
I am getting ready to install a rebuilt gearbox on the 912 ULS on my experimental aircraft and am unsure about the proper torque for the crankshaft nut. I had read section 72-10-00 of the Maintenance Manual Heavy for the 912/914 Series Edition 2 / September 2022 to gather information about torque, loctite usage and so forth. On page 5 of 71-10-00 there is a diagram showing torque and loctite usage on an exploded view of the gearbox. The torque value shown there for the crankshaft nut is 300 Nm / 221 Ft Lb so that is what I was planning on using.
I watched the site video on removing and installing the gearbox to make sure I understood each step of the process and noticed that the video called for a torque of 150 Ft Lb for the crankshaft nut. Rodger Lee also quoted a 150 Ft Lb value in a thread about a year ago. That thread was later than the September 2022 MMH publication so I thought maybe I had old information but, as far as I can find that is the latest MMH.
I did find a value of 200 NM / 147 Ft Lb in the Maintenance Manual Line for the 912 series edition 4 / July 01, 2021 page 5 section 05-50-00. That is likely where the 150 Ft Lb value came from.
So, I have two Rotax manuals that seem to show different values. Which one should I use?
Thanks!