Stuffing Box Installation: The Wrong Way
A challenging stuffing box set up may require moving the engine to repack it.
Question: The photo here is showing the back of my boat’s engine and the propeller shaft passing through my stuffing box seal. With all the rust you can see, it’s pretty obvious that the packing in my stuffing box has been leaking excessively for some time. I tried to adjust the packing nut to slow down the leak, but it didn’t work. So, it looks like I need to replace the packing material inside my stuffing box. The problem is, the flange that bolts the shaft to the transmission on my engine is too close to the nut on the stuffing box. I can’t back the nut on it out enough to access the packing material inside the stuffing box. I’m hoping for a miracle solution here. Any tips?
Answer: Wow! You’ve been cursed by whoever installed the engine on your boat. I have bad news for you. The only way you are going to get around this problem is to completely unbolt the engine from all of its mounts and slide the engine as far forward as you can. Hopefully that will allow enough space to slide the packing nut up the shaft, providing access to the packing material inside the stuffing box.
One more bit of bad news here as well. You may also have to remove your boat’s propeller to allow enough forward movement of the engine/shaft assembly. This depends upon how much space there is between the aft edge of your propeller strut or keel exit point and the forward edge of your propeller. Judging from all the rust shown in your photo, you’re in for a bad day (or two) working on your boat!
- Ed Sherman is a regular contributor to boats.com, as well as to Professional Boatbuilder and Cruising World, where he previously was electronics editor. He also is the curriculum director for the American Boat and Yacht Council. Previously, Ed was chairman of the Marine Technology Department at the New England Institute of Technology. Ed’s blog posts appear courtesy of his website, EdsBoatTips.
Tags: boat maintenance, Ed Sherman, running gear, shaft seal, stuffing box