Going back to your original post, you indicated that you were having problems with shifting the shuttle. Again, detailed information is the key to diagnosis. That problem came on suddenly, or gradually over days/weeks of use? Only 400 hours on the tractor and it's nearly ten years old says you don't use it much. The difficulty shifting. Was/is this mainly when first starting up, putting it into gear, and then starting off? Or is it getting to be more like every time you stop, change gears or direction?
My guess at this point is the tractor has a fiber clutch lining. The facing may be developing a tendency to stick to the flywheel or pressure plate while the clutch is engaged. Not uncommon, even more so with equipment that gets little use. I would try "slipping" it a bit. Put it in a higher gear, hold the brakes, and let the pedal up slowly until the engine loads up. Hold it there a few seconds then push the pedal back down. Repeat that two or three times. It won't hurt much and might help burn off whatever is developing on the disc facing and contact surfaces. Also look for a clutch pedal latch. Many foreign built tractors now come equipped with a means to hold the clutch pedal down during periods of non use. If you don't find one, I suggest you fabricate something. Even as simple as a piece of two x four cut to length so it fits under the seat and keeps the pedal on the floor. I think it would be worth your while considering the amount of time the tractor sits unused.