The past couple times I have used my RGR1258 tiller, I have noticed the gear oil looked milky white. The first time I noticed it, I removed the plate to the gear case and cleaned out the milky oil and put fresh oil in. I used it to till my garden. Then about a month later I noticed it looked milky again. So I opened the gear case again and it was, in fact, milky white. I cleaned it out again and replaced with fresh oil. I checked the rubber gasket between the cover and the body of the gear case and found it to be in good shape. I removed the vent plug and thought maybe moisture is getting in there. I also noticed after using the tiller, gear oil runs out of the vent plug hole. I only put the required 3 qts / 6 pints in there. So I know it doesn’t have too much oil in it. At first I put thread tape but then removed it because that would defeat the purpose of the vent plug. So I am curious, is there a liquid sealant I can put on to keep this from happening or is this just part of it?