Little by little .....
..... packing glands will leak more and more. If you are only leaking about one drop per second, I don't think you have anything to fear before your coming haul out. Any changes will come slowly.In my own personal opinion, I would go for the new dripless teflon dough like packing to keep the bilge dry. Although I do not have a mechanical shaft seal on out 1999 H310, I have had considerable experience with mechanical shaft seals on industrial pumps, both large and small and what I have seen in the field keeps me from ever installing one on our boat. I know this will not sit well with those who have switched over but, these seals do wear and do not last forever. When they eventually do fail, it is often without warning and often with MAJOR leakage. This of course cannot be repaired while in the water while a packing gland can.Regards,Island Hunter