Something else to add to you preop checks Hydro piston rod and rockshaft yoke

[pfrederi 17,114]

Had a first time failure today.  Just as I finished 2 hours of snow flake rearranging the blade dropped on my Chrager 12.  The hydraulic cylinder piston rod had unscrewed it self from the yoke that connects to the rock shaft.  easy fix but something I need to remember to look at before I start out in the future to see if threads are showing.  When things warm up and dry out will have to look at some loctite on the treads.

[Ed Kennell 35,483]

That is surprising.  I never would have guessed the cylinder would rotate enough to back itself out of the yoke.   You would think cylinder extension stroke would retighten the yoke. 

[Adams94 1,065]

I had this happen over the summer on my C-160 hydro while mowing.  The yoke just came off, threads were good, so I put it back on and no further issues.