Originally posted by jk3rwood but this issue is totally non-existant when in Liveview.
Liveview uses a different focusing system and is not affected by AF fine tuning.
Originally posted by jk3rwood Could the autofocus drive within the lens itself have already gone out?
Not likely but the lens could have gotten bumped or damaged in some fashion that has knocked it out of alignment. (I know you take good care of your gear, we all do. But sometimes things happen we do not notice).
Originally posted by jk3rwood However any advice at this point would be appreciated!!
Suggest you try the AF fine tuning route and see if that helps. You have nothing to lose at this point and it might work.
I find the situation very odd however. You say the lens works fine in Liveview but not in the viewfinder with both cameras. Since it does work in Liveview that essentially eliminates the lens as the problem. My next thought would be some dust in the AF sensor of the viewfinder causing things to be erratic. But you say it is soft using the viewfinder on both cameras which is not what I would expect if it was dust or a hair in AF sensor
Anyway, try the AF fine tune and see if that helps. Do read up on the instructions for AF fine tuning, it must be done in a VERY precise and controlled manner or you are just guessing. Must be on a tripod, must use a focusing target, must be precisely aligned in both vertical and horizontal planes.