I also don't agree with that fake intelligence rambling ... My Massey Ferguson GC 1725 MB TLB came with no such "advise"!
And I liquid filled my rears ... And added 3" spacers ... Then I added ... factory steel wheel weights ... !
I think the weight of my axle, spacers, wheels/tires, liquid fill, and wheel weights are much less weight than what the weight the axles bear when the tires are on the ground, and the full weight of the tractor and operator are bouncing over uneven ground ...
Here are a few possibilities ...
1. Maybe Massey Ferguson builds a stronger tractor ...
2. Maybe I just haven't jerked it around hard enough in the 735 hours I've had it since new?
3. Maybe I just need to put more hours on it?
4. Maybe it's a very rare occurrence due to a bad/faulty axle breaking, and the other hundreds of thousands of S/CUT Kubota TLB'S haven't broken an axle even with liquid filled tires? (Never heard of a stabilizer breaking/bending)
5. Maybe they are just covering there backside worried the extra weight will be too much if the operator is already over 500 Lbs ...
6. Maybe it a mistake in the manual (I've found things that were wrong in manuals!)