I just installed and shimmed new main bearings with a freshly turned crank and when I tightened them all down it wouldn't turn over. I loosened one at a time and when they were all loose it turns. Then I tightned them one at a time and it turned harder with each cap and when all were tight it wont turn. I used plasti gauge and clearance is .002 on all. I had everything clean and oiled, then I took it apart and used a thin layer of assembly lube, no difference. I have the new rear main seal in an I am sure that stiffens it up a little, but what gives?
