Preparing the Engine for Removal

Momentum is a funny thing. When doing a major boat rebuild like this, momentum counts for a whole lot.  More often than not, each project reveals 10 more problems than you first expected. Each time these problems come up, momentum takes a hit and motivation goes down hard. Recently I've found myself half finished with many of my projects by hitting roadblocks, and I feel a little lost on where to spend my time on the boat. Whenever I find myself lost, I revert to taking things apart inside the cabin. It is relatively easy work, and I feel like I am getting things done. However, these are mostly cosmetic issues that won't get the boat back in the water anytime soon. So with the weather cooling down, I decided it is time to focus my efforts on the monolith that is the Yanmar 4JH2E - my diesel engine. Not just the engine, but the entire engine room needs work before we splash. One primary issue in there is the need to replace the stuffing box. I could probably refurbish it, but will most likely go with a PSS shaft seal as a replacement. If you go back to the posts when I hauled out, you would see the broken propeller shim that caused a lot of vibration of the shaft and engine. This caused the shaft seal to leak, which in turn sprayed water all over the engine room. Unfortunately, to replace the stuffing box the shaft must be removed. In order to do so, one of 3 things needs to happen: remove the rudder, remove the transmission, or remove the engine all-together.

My plan for the engine is to completely clean it off of old paint and rust, replace all hoses and clamps, replace the rusted and busted air intake, and do some general maintenance on the engine. I might go as far to replace the seals/gaskets, refurbish the heat exchanger, have the injectors inspected, and who knows what else. With all of that in mind, I decided it would be easier to just pull the engine so I can have easy access to all of the engine itself, and the entire engine room for cleaning (room and bilge), rearranging, and painting.

So with the idea that the engine is coming out of the boat, I began to have some mental momentum of things that need to get done. First step is to prepare the engine for removal by disconnecting all hoses, wiring and the shaft from the engine. I started by attempting to separate the shaft coupling from the transmission and then the shaft from the coupling. This job is notoriously difficult, and with my coupling being a ball of rust...it was a tough task.

Here is the coupling, stuffing box and shaft before any disassembly. Note all of the rust, especially at the set screws.

I started by applying penetrating oil to the coupling bolts, set screws and the shaft itself every day for about a week. I then needed to start removing the exhaust hose and muffler to gain access for wrenches to fit down there.

Here is the exhaust and muffler above the shaft:

With some brute force, the coupling bolts came off eventually. The set screws took a lot more effort, blood, and sweat to get out. One of them was easier than the other, both took vice grips to get them to budge. Here is the coupling after separation, and vice grips on the set screws.

Below the muffler was a plywood panel that capped the space where the stern tube is located. This wood was pretty much disintegrated thanks to the stuffing box leak. I'm pretty sure the exhaust leaked down there as well.

I then set out to remove the coupling from the shaft. The recommended trick is to set a spacer (I used a socket) set between the couplings against the shaft, and then crank down on bolts connecting the coupling halves. Cranking down on the bolts evenly would then push the shaft out. Unfortunately, I found that I have very little clearance between the transmission and transmission coupling to allow any bolts to be screwed down. I might be able to get it done by cutting some bolts to a precise size. I then realized that it was silly for me to be trying this hanging upside down in the engine room when I plan on pulling the engine out anyways. I'll attempt to remove the shaft coupling once the engine is out and I can do it in a more comfortable setting.

So with the couplings separated, I then turned my attention to wiring, hoses and the motor mounts. The front motor mounts are fine and I was able to crack loose the bolts, but the back mounts are horribly rusted. One of them is cracked, probably adding to the vibration I experienced when motoring. It now looks like I will have to cut the nut off the mount, and then replace the back mounts once the motor is out. Like I said...once you start a project, 10 more show up.

I plan on getting the engine fully prepped for removal this week. I go out of town next week for Thanksgiving, then when I get back its time for the pull. I am pretty excited about the pull and to begin the engine refurbish. Momentum is growing, and my enthusiasm with it.