Ditch witch sk 500 drive motor

[RDAA]

I just picked up a used sk500 with about 2000 hrs. The price was right it needs some love, runs great boom works great. When the right side track is loaded hard it basically stops moving and shutters. I ran it up against a tree the left side spun down just fine. The right side just shuttered. I could see it's not the sprocket slipping in the track. Has anyone had any experience with something like this? Is there any other source out there for orbital motor out there other than dw?