I have two fo these machines. The one machine has a nice nut/allen bolt into the pan and very easy to take off. The other machine which is 2 years older has a bad plug, very thin walled and hard to wrench it so in the past a vise has been used. Well it was beat up bad and finally used a chisel/punch to get it to turn. I ordered a new thru toro. Exact same plug, but now it seems to leak oil all the time. I have tighten it, etc but to no avail. Is there something out there that I can...say put an extra gasket/rubber/stopper on it to prevent it from leaking?