Allright, I'm on the flatlands of the Netherlands, so 4wd is only necessary to get me out of some mud. I'm going with the advice to just assume that it's not problematic. Thanks all for the advice!
I'm on my third Kubota and have a Ford as well. All of them have a certain amount of binding when run in 4WD. I've been taking care of the snow at our church and have been driving the last two (l3200 and l4240) roughly 1-1/2 miles each way to do this. Except for when the roads are completely snow-covered I use 2WD because there's enough binding to somewhat affect how the tractor operates. This is with the factory tires. There have been numerous posts over the years from people who have problems getting their tractors out of 4WD because of the binding. There is no doubt that using 4WD when there's sufficient traction does impart an unnecessary load on the drivetrain.
Of some interest, there's another thread going in which some posters are ridiculing owners for taking a salesman's advice of using 4WD only when needed to reduce wear.
One thing we need to remember is the tractors are purposefully made to have the front tires spin a little faster to aid in steering. Not a big deal in the dirt, but like you say on pavement it's pretty noticeable.
One thing we need to remember is the tractors are purposefully made to have the front tires spin a little faster to aid in steering. Not a big deal in the dirt, but like you say on pavement it's pretty noticeable.