I have a MX 5100 Hydrostatic, question about orbital steer controller. Pulling to right enough to be annoying, seems like the Orbital is grindy feeling, stiffer at lower rpms and not sitting still, less smooth as it used to be. Thinking the pistons/housing are worn. I have had similar stuff with crown forklifts and replaced the main hyd pump with a priority flow divider that would wear. Anyone have similar issues with orbital? Is priority flow in this unit or elsewhere? Don't think they're rebuildable, found orbital for about a grand, anyone ever change one? I can do it but pointers always are golden. Second question is if orbital is worn, wouldn't main pump have wear also, although not noticeable? Thx for any input.