As coincidence would have it I bought my M8540 at Barlows, also 100 miles away. In January they picked up my tractor, serviced it, and then brought it back.
One of the service items was a sticky hydraulic shuttle and shuttle adjustment. My shuttle shift had become stiff, and on a couple of occasions when I moved the shuttle to the reverse position the tractor stayed in neutral, I had to cycle the shuttle a second time for it to engage.
Barlow's found that the shuttle cable had corrosion and it was replaced with a new one. My shuttle is now silky smooth and properly adjusted. Fortunately, this work was covered under warranty. I did pay a reasonable pickup and delivery fee.