When changing the ATF on my '96 E320, I spotted a small drain plug with socket head. Having never enjoyed the experience of removing an oil pan while it's still full of oil, I gingerly loosened and removed this plug. The oil drained out, after which I proceeded to remove the pan, change the filter, and re-install the pan with a new gasket. The little drain plug seemed flimsy to me, though, almost as if it wasn't designed for regular removal. I reassembled and inspected several times for leaks and never found any. Now, 25K miles later, I noticed a wet spot spreading from around the little plug -- as if it's seeping a bit. It's not enough to drop on the floor, but enough to make a large damp circle around the plug. I'm going to change it again soon. Should I replace the plug? Is there a replacement gasket for it? RTV it? Did I do a bad thing? Thanks,
John