While researching Harley primary chain case oils I discovered quite a few Harley guys are using ATF in they're primary chain cases. I was all set to use the Harley brand of primary oil but the favorable posts concerning ATF in the primary got me to thinking....LOL! Theres a sticky section on the VTwin forum I frequent about using it and alot of guys use it and swear it's the oil to use in a Harley primary chain case. It seems the consensus is to use the Dexron/Mercon flavor but a number of guys like the Ford F and the Chrysler atf plus4 as well. It seems the Dexron/Mercon gives a smoother engagement as opposed to the Ford or Chrysler which engages the clutch more aggressively for drag bikes or for a more aggressive type of riding. Does anyone here have experience or opinions on using ATF in a Harley primary chain case? Thanks