Well weekend tasks came to an abrupt end last night. I was doing a little landscaping work trying to remove a shrub root with FEL and felt a sudden lurch. i looked back and the right rear tire was not where it was supposed to be. I was in MFW drive low range. Discovered to my dismay that the rear right axle shaft had snapped just outside the differential seal. The tractor was purchased in 2014 and only has ~150 hours. Well maintained and garaged. I do use the FEL to its limit along with a pallet fork for lane gravel and firewood carry. I also bush-hog seasonally but no regular lawn mowing. I take good care of my equipment and tend to keep things for a long time. I am also fairly pragmatic about machines, things break and wear, and you fix what fails. But this kind of failure seems to me to indicate an overweight or over stress on the axle. That got me thinking maybe I was asking to much of this tractor. Rear tires are liquid filled and I do routinely carry a full complement of suitcase weights (8x42 lbs) on a Heavy Hitch on the rear three-point arms. Those rear weights make all the difference in stability and FEL safety. I would not think that ~350 lbs would cause undue stress on the rear axles but this kind of failure makes me wonder what happened. Is this rotational stress? What is the thinking here? What causes this kind of failure? Is this accumulated abuse or something acute?