Pat, I just went down stairs and stuck a 17 mm wrench on the left hand upper motor mount bolt on mine which is not even torn down. Of course the infill panel is off. 17 mm 12 point. feels a little loose like it might be 16 mm but I did not have one on hand. Most likely its in the garage and I am in my house coat. I will see if I can find one once I get my uniform on. This would be the only time I do not always use a 8 point wrench. Anyway it just has to hold it long enough to bust it loose. then you can hold it with you finger. Let me iron my uniform and I will see if I have time to round up a 16 mm wrench.