NH L783 skid steer. I've had this machine for 20 years for personal use around the house and helping out a neighbor or two. Well, while helping a 70 year old windower take her over grown privy bushes out i started losing power on the bucket. It whines/rattles while under light load but still operates but at 1/3 of the speed /power.. As soon as you shut it off and start it right back up it goes away, works fine for awhile then comes back after a little use. No leakes, fluids are all full. Not sure where to start looking for the issue. Any and all help would be great. Ross