<font color="red"> I need both on my DX33. With only filled tires, the rear end will instantly lift off the ground when digging into a pile of dirt. With filled tires and a 400+ lb BB I still have to be cautious not to stop quick with a loaded bucket or lower the bucket to fast. </font>
Boomerang1, the 14LX loader you have is an exceptional loader for a mid-frame CUT. I find the same thing applies to my 12LA on my small frame CUT. Both are CNH products and really are beasts for their size class. My manual states I need wheel weights + ballast box -or- fluid fill + ballast box. When the loader is well matched to the tractor, there is no question you need both. CNH tractors are fairly heavy, not as heavy as some, but heavier than most, and still they need a lot of ballast to balance the FEL power.
While I am not sure about CUT weight distribution, I recently dug up information that for AG tractors that are 4wd, the ideal weight distribution is 60% on the FRONT axle, and 40% on the rear. For FEL work, that is far from ideal. But as I look at most CUTS, I wonder if that is pretty close to normal. Compare a modern CUT to a Ford 8N or similar older AG tractor and it becomes obvious that the weight distribution cannot be the same. The old iron had huge rear wheels compared to similar HP modern CUTs for traction, our new machines have 4wd for traction and the % difference between the front and rear tire sizes is much smaller on a modern CUT than on an older tractor. I think what it boils down to is that I belive small tractors are inherantly front heavy due to their 4wd design, and regardless of if you have a lightweight B Kubota or a heavy Mahindra, you need proper ballast to balance your load.