Did your autosiphon come with a black removable tip at the bottom end? This part is very helpful at reducing the amount of yeast that gets sucked up into the siphon. Also, the slower you draw from your vessel into the keg reduces the chance for yeast to get sucked up due to decreased vacuum. I also hold the autosiphon up to keep it off the bottom a little bit.
Hope this is helpful.
Put it all in the primary, and let the BeerGods sort it out