Has anyone experienced problems with a worn input shaft coupling at the HST end on their 273 HST? I've found out that the rear coupling on my input shaft only extended half way over the HST spline. Now both the input shaft coupling and half the length of the HST spline are worn away. The result is no forward or backwards movement and no PTO spin - an unhappy tractor! It looks like I can buy a new input shaft coupling, but replacing the worn spline on the HST unit looks like a real problem. Do you have to replace the whole HST unit or is it possible to take the HST unit apart to replace the spline?

Please help!