So I just replaced both differential output shaft seals on my 2008 E60 535xi 5 spd N54 sedan (200,000 mi). When I seat the side-output shafts into the diff (circlip goes click) I can hardly turn the shafts now, binding bad. The output shafts turned fine previously. Any ideas on why it would be suddenly very hard to turn the shafts? Is this just a normal stiffness after replacing those seals? I had both output shafts out at the same time, is that a problem?