If I had a lit work bench, cleaner, grease, tools I would take it all apart. It probably needs bearings. I do think a new tool is a good idea. Currently borrowing one to finish a demo in bathroom. Wish I had my selection of SDS bits. Oh well. It was a tool that probably had issues at his old job. Yes it's dirty. He does need one but I think one of his helpers when he pours cement owns this one. They tie in the skabs to the house with like 1/4 dowels. Not rebar, no texture so small. And the mesh they use in the slab is so thin.