Dripless shaft sealsДripless Shaft Seals are an alternative to packing glands. Avoid such problems by simply replacing the packing on a regular basis. Keep compressing it and it will eventually score the propeller shaft, which will then have to be replaced before the stuffing box will seal properly. This works to a point, but as the packing gets smaller it also gets harder. When this happens, most people simply tighten the packing nut(s) to compress the packing material and stop or reduce the leak. Packing material will harden over time (as the lubricant dries out) and gets worn away by shaft rotation, allowing water to pass and enter the vessel. A leaking stuffing box can cause a number of issues, from corrosion (the spinning shaft slings excess water all over your engine compartment) to sinkings, particularly if the boat is left unattended in the water for longer periods of time. More than that amount (say 10 drops per minute) or drips while the shaft is not turning indicates the need for adjustment and/or maintenance. Water helps lubricate the packing material so its OK for a stuffing box to leak a few drips (3 to 4 per minute) while the vessel is underway. The shaft log hose (which connects the stuffing box to the hull in most installations) should also be inspected for deterioration due to age (a common problem), corroded hose clamps, etc. Most packing consists of a square plaited material and comes either as traditional greased (or waxed) flax, or a more modern version impregnated with Teflon.Д¬orrosion and leaks are common problems youll encounter when inspecting your stuffing box. The more you tighten either type of gland, the more the packing gets compressed against the shaft. Another common style features a tightening arrangement that uses a plate secured by nuts and studs on either side of the shaft. The shaft is sealed by compressing packing material against it, most often by using a hollow nut that screws onto a matching fitting attached to the inboard side of the shaft log hose. The purpose of a stuffing box is to allow the propeller shaft to exit the hull while keeping water out. Thats where your stuffing box will be (unless you have a newer, dripless style shaft seal installed instead). To locate yours, trace the propeller shaft from the transmission to the point where it exits the hull. Only boats with inboard engines have stuffing boxes.

Stuffing box shaft seal